Typically the 'supported' being removed doesn't necessarily match to 'working'. So it may still work on RHEL7 systems, but you wouldn't be able to log tickets/issues with the support team to have it addressed and there wouldn't be security fixes released targeting RHEL7 specifically. While you might still be able to get it to work, you are essentially operating in an unsupported fashion on those systems.
For SCE, I believe this also means that there are no longer acceptance tests being run against RHEL7.
That being said, my understanding is that for EOL platforms there is the option to pay for extended support on EOL systems. I'm not in sales so I don't know the details of that, but the account management team can probably help out with that if you want to still get support for RHEL 7.