When HET bought Caesars my host advised me to "cash out" my comps and I went on a shopping spree at the Caesars gift shops buying cameras, clothing, cologne, perfume, bathrobes, etc with my stashed comps.
It makes no sense to hang on to comps. These days I take my extra comps and get Shell gas cards, and with premium now at $4.239 at my local station which I need for my car (reg is $4.049) I like having the gas cards arrive in mail a couple of weeks after each casino visit.
edited to add: but one thing new owners do NOT want to do is alienate their loyal customers. If they are smart they will honor the old comps, old player points, etc.
Remember when GM went bankrupt. Consumers who had the GM MasterCard did not lose any of their "points" towards a new car. They were protected by the bankruptcy plan. The "new GM" said losing those potential customers would be a mistake.