They made a new 50mm prime. By all accounts it's an incredible lens. Sorry, the future is here. If you want the best lens, you have to upgrade. If IS is what you're after, all signs point to future mirrorless cameras gaining IBIS.
If you insist on staying with EF, you can always buy an EF 50mm f1.2, which is, for all the grief it gets, still a perfectly competent lens. But to expect Canon to spend all this time and money developing a brand new 50mm for the RF mount, and then circle back and develop an additional entirely new 50mm for a lens mount that is on its way out, sorry, you're dreaming. (And no, they couldn't just make the RF 50mm into an EF lens due to how far back in the lens the glass elements extend.)