Regionals are trying to get candidates emotionally invested in their particular company as early as possible... get 'em on the hook so to speak.
If there is financial consideration provided for basic flight training, then there will be an obligation, which is reasonable.
I would not accept any sort of obligation for anything other than cash or flight training below the ATP level.
Some programs may offer a slight benefit in seniority, it's OK to do that as long as you were going to work there anyway.
But your choice of regional employer should be based on career progression considerations to the majors (and geography if that even matters to you, typically more important for older folks with families). Avoid the usual bottom-feeders in most cases.