[NeedMoreTea]

Freedom to what though? I'm at a loss why a structure that's OK for FF, is not OK for TB.

...unless there are plans for profit and charging a subscription or some such.

[Macha]

Firefox is under Mozilla Corporation, which is owned by Mozilla Foundation.

Thunderbird will now be under MZLA Corporation, which is owned by Mozilla Foundation.

Why not put it pack in Mozilla Corporation? Because Mozilla Corporation has tried to jettison it a few times for not aligning with their goals, I guess?