Regardless of your point of view on whether people should be allowed to use tmorph and similar things, it does seem a bit shitty to tolerate that people use it for over a decade before randomly just banning outright for 6 months with no warning at all.
A warning, rather than a ban, is the way to go. If people want to continue using these things after the warning, then by all means ramp it up to a ban. But this random zero tolerance ban after years upon years of allowing people to use it was a little heavy handed