If you're hunting May/June, and the laws are supposed to come into effect July 1 what's the problem? Don't panic about it. Get all the right documentation, eg proof of ownership of your right in the USA, plus the other required docs for the countries you are hunting.

If you between the lines I feel the new laws are aimed at the "importation" of rifles rather than the sport hunters coming in and out. I don't think these countries are going to put their safari industries at risk.

This might all be settled and history by May.

You may find you will loose your deposit if you cancel for just the reason of not being able to use your own firearm.

Speak to your outfitter and agent.