The EOS R50 has the RF bayonet. If you have EF-M lenses, you can no longer use them on the R50. If you use EF/EF-S lenses with the EF-M/EF adapter, you can continue to use them on the EOS R50 with an RF/EF adapter. Otherwise you will have to use RF / RF-S lenses. Here the choice is getting bigger and bigger. As the EOS R50 is a small, compact camera body, you should concentrate on RF-S zoom lenses, which are compact and lightweight. This allows you to cover a broad spectrum, e.g. with the RF-S 10-18 mm, RF-S 18-45 mm and the RF-S 55-210mm. In contrast to the EOS M50 Mark II, you can also use all other RF lenses with the EOS R50 without an adapter. However, the difference between the two bodies EOS M50 and R50 is not very big.
I would therefore recommend the EOS R6 full-frame camera, which is currently available at a very favourable price and is a quantum leap compared to the EOS M50 Mark II. I would continue to use the EOS M50 Mark II as a second/travelling/hiking camera. The same applies to the lenses as for the R50 with the exception that you cannot attach RF-S lenses, only RF lenses or EF lenses with an adapter. Here too you have a good choice, which is growing.

Yes that's right