Neither "mundane" nor "supramundane" teaching, neither "conventional" nor "ultimate" teaching rejects the teaching of rebirth.
The "ultimate" teaching is just more precise and talks in terms of mental & physical events, while conventional teaching uses ordinary words (such as this person was reborn as a frog, etc etc). In both cases they refer to cittas, cetasika and rūpa.
While mundane teaching is often aimed at showing the path to better rebirth, the supramundane teaching is aimed at stopping rebirth all together.
So in all cases existence of rebirth is accepted.
"Life is a struggle. Life will throw curveballs at you, it will humble you, it will attempt to break you down. And just when you think things are starting to look up, life will smack you back down with ruthless indifference..."