Yes, the assumption is correct. See my recent comment on changeset/125817813.

I "became aware" of this changeset a couple of weeks ago and my view on it is that DaveF's reason for the change as described in his first comment here is correct. But I'm not sure that making such a wide change in one go was such a wise idea although from the conversation it appears that only one case (highlighted by ohmanger) was actually wrong although several more are disputed.

I have recently "been reminded" of this changeset so I looked at the changed ways and I have to admit that for two ways I was the previous editor.

For way/1054074314 it was not me that added the 'access=private' tag but I can confirm that it is now "highway=footway" and can see in version 7 of way/22969049 that it used to be "highway=service". SomeoneElse recently reverted his previous reversion on the same basis.

For way/993439675 I made the edit that introduced the 'access=private' tag. More accurately I changed the highway type and left the previous access tag. The history of way/30074297 shows that version 7 used to continue to the road but my survey showed that it no longer did so I changed it to a footway. DaveF's change here was correct, it was my error not to have removed the access tag when I changed the highway type. Hopefully SomeoneElse can revert his previous reversion here too.

Thanks for the fix, I don't really know what happened there - I edited with StreetComplete and then with JOSM so it looks like a conflict resolution went wrong.
For the node/8316970046 I disagree with the deletion of the crossing - there is a path on one side of the road and a sidewalk starts on the other side of the road at the same point. It is a place where people are expected to cross and therefore surely should be marked?

Not just an implication, it is spelled out in words in the description: "Restricted Byway No.14, Hyde runs parallel to and abutting Hertfordshire Restricted Byway No. 005, Wheathampstead.". I've never seen that before but I'm not sure I've seen a RoW shared by two counties either.

It was my GPS track and I was on foot.
My track that day looks a bit wobbly everywhere not just here. If you have alternative data it probably is better.

I've done some more research and "impassable" seems much more commonly used than "inaccessible" (although still very infrequent) so I have changed the tags to include this instead. I also made the tagging more consistent along all three arms of the stream.
I'm not totally happy with this but I know of no other way to represent both the legal and physical aspect.

The standard UK tagging for a bridleway RoW is foot=designated, horse=designated, bicycle=yes which is what I normally use. However this is a bridleway that runs along the bed of a stream. At one point it passes under a bridge around 1m high and in other places is only around 30-40cm wide at the base with almost vertical banks for 2m. This makes it inaccessible to horses or bicycles so I added those tags as well. If I tag it as horse=no then it would not reflect the legal position. If I tag it as horse=designated then people could be routed along it which would be wrong. I have used the set of tags that I think most accurately represents both the legal and practical situation (although having looked now I see that I have not been totally consistent with the bicycle part on the various sections).

Reverted, see note/2183218 for details.

This change moves a section of the Hatfield road north by several hundred metres. I have reverted it in changeset/96190240.

If you want wiki references for this information there are very good UK specific ones:
osm.wiki/Access_provisions_in_the_United_Kingdom#Public_Rights_of_Way
prow_ref=*

You have changed some things in this area that look better on the map but are not correct in the OSM data structure. The highway tag should be the physical type of the highway, not the type of right of way on it.
Footpath 42 and footpath 44 are private service roads that have a public footpath on them, they should be tagged as highway=service, access=private and foot=designated.
Bridleway 10 east of the farm is a private farm track with a public bridleway on it, it should be tagged as highway=track.
All of these highways already have the Hertfordshire Parish Council references on them in the prow_ref field, it should not be in the name field (just like on the motorway where M25 is the ref, not the name).

Sorry about breaking that, I have made a fix for it. The track is clearly private and I don't think the right of way (bridleway) goes along it. I have added a fixme tag saying it needs to be surveyed.

I'm sorry about breaking the relation for the route, I hadn't noticed that.

What I did notice when I walked here was that the public footpath does not go across that bridge as I had drawn it originally. Instead the public footpath runs along the new way/460344329 that I created (the signpost on the street told me the correct location). I removed the old foot access tags on the assumption that my original footpath tagging was incorrect.

I must admit that I don't know whether the Lea Valley Walk should follow the public footpath (which seems sensible) or follow the original bridge. Since it approaches from the south along the road I guess the public footpath makes more sense.

Shall I change it or will you?