I did read the wiki thoroughly beforehand. As the wiki also states that "Guidance systems can be either physical, such as kerbs (in American and Canadian English, "curbs"), or remote, such as optical or radio guidance."
In the case of the system in question, it's presence of physical curbs, with special tracks (not normal paved roads). There are sections that are normal bus lane, which were tagged as that, while other section of the system would therefore qualify as bus guideway under the criteria on the wiki.

Hello,
I am aware of the classification and believe it to be appropriate. Several sections of the BRT system runs on dedicated curbed "tracks" that are paralell and separate from the roadway and are therefore not normal bus lanes. Hence, the highway=bus_guideway tag seems appropriate. Further, the same tag is also already used on other sections of the system under the same case.