Landlord Tenant question -- I am the tenant, the Landlord notified me by phone/email he has a mutually executed sales agreement to sell the home

- he called me 31 March to tell me the house was under contract to sell, closing 28 Apr - in same call, he asked me if I could be out by 27 April as the buyer wants to move in 28 Apr - I agreed to all the above (we bought a house since he told us he wanted to sell) - I requested a lease termination agreement and when he did not respond, I sent a signed lease termination agreement with his requested dates for walk-through/key surrender/tenant vacate - he says he won't sign the lease termination agreement until after the property closes as he intends to keep collecting rent if the sale falls through for any reason - can he keep our deposit/demand rent if the home doesn't close for some reason? It does not seem reasonable to verbally/email ask the tenant to vacate by the day before closing yet not sign a lease termination agreement