I can confirm categories are not being suppressed currently from the homepage (latest) on the following version:
Discourse 1.5.0.beta8 - version 1a223b9d10cdfd55898c25f9217a54153a373039
This is assuming the Discourse instance doesn’t need to be restarted to see the effect.
I can’t update to latest currently - but will do later to see if the problem is still there.