My friend is seeking my opinion but i really don't know how to answer him as recently i was involved in buying a house while not selling.

Conditions as below:
He has a condo unit for sales and engages a PA to be in charge of that
He will be moved away in 2 months' time
PA told him only do listing after he is moving out, meaning to say that PA only do promoting after 2 months
He is shocked after listening it but didn't want to ask further before he has better picture of PA habits in his mind

Now he wants to know why some PA doing in that way. I myself don't know the reason behind but my opinion is PA can do listing and bring interested buyers for viewing even though landlord is still staying there.

So why PA do like that? Should i advise him change PA?

change your friend. simple decisions like this also cannot make his own mind.

if he wants to list now then he just instruct his PA to do so.

We are curious to know why if go to ask PA himself sure bluffing you

Not sure what is the PA reason, but in most cases, once a listing is obtained, work starts.

Speculating ...

Since the seller will be away, he may want to use the unit as his 'own' while working on it. Free rental, I guess for few months or even a year since property transaction is lower.

He may advertise temporary as homestay accomodation pending a sale...earning extra income at seller expense.

Use speed home la. kaodim.. why bother PA. Now alot PA sucks.

frankly, this is a stupid question.

if the "PA" does not perform what "your friend" expects then just shop elsewhere.

why "your friend" is short changing himself/herself?

"your friend" is boss or "PA" is boss

anyway, he has opt to other PA.