This would be disastrous for the reputation of the language and the company. The support burden would be enormous: they’d have to carefully investigate and document every corner of the framework that isn’t thread safe, and then prepare for the onslaught of feature requests to make this or that compatible with threads.
Xojo would get a reputation for “that language that makes apps that are always crashing” and “good language, half-baked thread implementation”.
Do it right or don’t do it, I say.