Making a late entrant "post or wait" has been trending in different regions lately. I have seen it in PA, DE, OK, KS and MO. This is a house rule, the TDA does not give any direction for late entry other than full stack. I think it started from some online sites where if you entered late you weren't dealt cards until the next big blind. The only reason I think it caught on is to quiet the complainers who thought it wasn't fair for a late player to be dealt in with a full stack without penalty; which is of course shortsighted as coming in with 10k chips on 200-400 is much different than coming in with 10k chips at 25-50 at the start...
Having done it both ways in tournaments I've run, my recommendation is to put the stack down and just deal them in right away as long as they aren't in between the button and small blind. By NOT making them post or wait, you save yourself from A) holding the game up while the player decides or B) the situation where the player who buys in runs off to the bathroom or somewhere and doesn't take their seat right away and is not present to choose to post or wait.
Chips on the table should be dealt cards, if eleigible, period; your tournament will run the best if this happens.