If you’ve got dark hair, then yes, it’s absolutely worth it. It’s something you can do to “start the ball rolling” before HRT is accessible, and HRT doesn’t really make much of a difference to the long term outcome you’ll get from laser.
But what gives me some hesitation and doubt is that if I start laser hair removal without suppressed T that completely new hair follicles would grow which would ruin the results of previous sessions. Is that possible
Nope. Once a follicle is down, it stays down. However, hair grows in a years long cycle, which is why it takes multiple sessions spread over time. Even if you get all of the active follicles (which you won’t. Laser will get most of them, but not all of them), new hairs will become active every month.
HRT can turn terminal hair follicles (the thick darker ones) in to vellus hair follicles (the light thin ones), and it can slow down regrowth, but both of those effects are minimal on facial hair