Can a creature transformed by the true polymorph spell use Legendary Resistance?
The "Legendary Creatures" section of the introduction to the Monster Manual (p. 11) and the corresponding chapter of the basic rules includes this line (added in the first MM errata from 2015):
If a creature assumes the form of a legendary creature, such as through a spell, it doesn’t gain that form’s legendary actions, lair actions, or regional effects.
Which doesn't seem to state anything clearly and specifically either way regarding legendary resistances. So can a true polymorphed creature use Legendary Resistance?
Link to relevant question about other legendary abilities: True Polymorph: can a player use legendary actions of its new form?