They may well be lying about their reasons/justifications, I don’t have any way to know one way or the other.

This just isn’t a new thing. Companies fave been blaming the high cost of supporting the relatively small number of users on an “alternative” OS for a very long time. Unfortunately, I think that as long as desktop Linux is in the single or low double digits of percentage of users, this is something we’re going to keep hearing.

A company is unlikely to do a thing if it’s cheaper to not do the thing.