This is reasonable since it displaces the homeowners and pets (if applicable) for approx. 3 days. Food has to be double bagged, pilot lights turned off, opened wine or liquor bottles, spices, etc. must leave the home. Plants (indoors and outdoor) must be watered well to protect the root system. 

Hi David-Very curious...why have you not used a buyers' agent for your own protection? (Not just talking about this termite issue).

The sooner the Seller treats these termites, the better.  I understand this is not only one treatment, but a long term plan, so you may speak to a local exterminator and ask them about the treatment plan they recommend.  May ask Seller for 1 year contract thereafter...depending upon what your exterminator says. .

I'm with Cindy.  All of this sounds normal and appropriate.  

If I were the seller's agent, I'd have asked that possession be COE plus 3, meaning that the seller will still have possession of the property 3 days after close of escrow.

I'd have the tenting already arranged to occur the day after COE when the seller has already vacated the property.

To answer your question, no. I would never ask a seller to spend thousands of dollars in treatments until the contingencies are removed. I would handle this the exact same way.

Good luck.

Parked and reading