I assume QR Silver status after Oct will be identical to Emirates, hence lounge access will be limited to Doha. I do hope Qatar's new airport will provide Silver Members a lounge that is identical to an Emirates Lounge otherwise Qatar will certainly loss a lot of customers. I imagine Qatar have already ended most of their contracts with other lounge providers around the world and are now in the process of sorting out access to various One World Lounges.

In your case they won't stop your lounge access, but if you travelled the next day you would certainly be in for a nasty surprise.