The unwieldy order of canon "priority" I personally like to use: Golden > the P4 side of Ultimax > Aigis' Arena story mode > Yosuke's Arena story mode > the P4 side of Q > DAN > The Magician > everything else.
Maxed social links with everyone, most importantly all the characters Yosuke would have been or become aware of (himself, schoolmates, the Dojimas, Marie, Adachi, Shu and the fox).
Magician hit max at some point around July.
Marie was rescued, so everybody remembers her.
Yu's birthday is sometime around August, making Yosuke the oldest on the team.
( minor stuff )
General headcanon
Something ambient in the TV world besides the fog induces the same sort of fight or flight response that an Evoker is designed to, except it's constant and everywhere. This gives a handwavey explanation for why the kidnapping victims seem to have a worse time than most of the people around town in December, but more importantly would imply that there's nothing inherently stopping any of the P4 kids from summoning Personas in the real world apart from a lack of training.
Lack of training is the reason the P4 teams' evolved Personas appear to be temporary. (They don't appear in the sequels, and they don't start out evolved in Q even though one or two characters make reference to events that happened in their maxed social links.) Once the potential is unlocked, the evolved forms can be summoned at any time, but it requires particular and usually unnecessary focus.
( minor stuff )