Recommended for admission? What does it mean?

[2021NeuroMPH]

Hi 

I got an email last week from the POI saying she's happy to supervise me for my master and asking if I'm still interested and will let the department know. I replied yes and would accept the offer when it comes (it's my top choice so of course).

I've been checking other posts and it seems like that doesn't 100% guarantee me a spot. What do you all think? Should I ask the program? it's getting super late and I'm anxiously thinking things could go wrong...