This is very common

Basically just a semantics type deal. Usually the player's "people" whether a parent, relative, or former HS or AAU coach starts reaching out to programs en mass of potential interest making it known the kid is going to be transferring well before he actually makes it official/actually enters. This is easier than ever in the digital age. This even happens for major college kids looking to transfer down to the mid-major level. This allows kids to sort of explore what potential interest might be out there for them, talk about it with their family or confidants without formally entering and basically hitting the point-of-no-return/pissing off their current team if they end up wanting to return. The number of kids who are 99% transferring after a long, grueling season and end up staying at their respective school is a significant number.

I'd estimate that up to maybe 25% of kids already know which 1-2 schools they will likely attend the minute they officially submit to the portal. It's also why you see so many kids announce their new school within days of even officially entering the portal.