For sure its possible to be a long term winner without using a HUD, and some sites dont even allow them which makes the choise easy. But that being said on sites, that do allow HUDs, I certainly think, its an advantage to use them also for MTTs.
Like any other tool you just need to learn how to use it to avoid overadjusting based on questionable data. Its true, that tournament play change with stack sizes, ICM-pressure and number of players on the table, and this does blur HUD-data somewhat.
But even so if someone has only 3-bet one out of 78 opportunities, and now you face a 3-bet from this person, do you really think, he is messing around? Chances are, he has the goods, and it would be silly to not adjust the range of hands, you give action with.
A big misconception among many non HUD-users is, that HUD-users rely on the HUD for every single decision, they make at the poker table. But this is far from the case. The vast majority of decisions are based on stack sizes, hand strenght and board texture, and the HUD is only consulted for decisions, which are close and can go both ways.
But even so if using a HUD can help you find just 1-2 good spots more per tournament or get away from someones aces or kings as in the example with the tight 3-better, this already gives a significant boost to your winrate.