Buyers of home want to move items in before closing

[Tom Fidrych]

I'm in the process of selling a home. The buyers had a contingency of closing on their place first, using the proceeds for 15% down with 85% coming from a Fannie loan. Their home just closed and they are renting their house from the buyer for the next month. We were to close on June 4th but because the sale of their place paid off a Fannie loan that was in forbearance, Fannie now requires there be a 30 day waiting period  before a new Fannie loan is issued. We extended the closing date to July 1st and had the buyer surrender the $2k in earnest money in the event the deal doesn't close.
The buyers agent is asking that they be allowed to move their items into the house on June 28(but not occupy it), 3 days before closing, to help them with the move. They are an older couple and will need 3 days to move.
So they have possession of 15% from the sale of their place, are approved for the loan and seem excited to move in but I'm reluctant to allow their items to be placed inside before closing. If I allow them, should I ask for an increase in the earnest money.