For those who have 1st GEN Ryzen and want to upgrade to ZEN 3 (4000).

If you have a gen 1 ryzen and you wish to upgrade to ZEN 3 when it lunchesbut you cant purchase a motherboard and a CPU at the same time and you are afraid your (b350,x370,b450,x470) wont be fully supported, also if you dont want to leave features in the table, then you can purchase an x570 (possibly a b550 as well but I am not sure about this as I did not tested this configuration).
Just to let you know 1st GEN ryzen CPUs work without any problem on X570, no stability issues, and more... memory overclocking is better, I couldnt go higher than 3200 MHz on my x370 with, more than that and it wouldnt boot no matter the timmings, voltages, LLC or other parameter I changed. Now just as easy as activate xmp, then get the voltage higher...then set the frequency...for example with no tinkering but the Voltage I just dialed 3600MHz and it booted, no it was not stable, but it's a question of adjust the timmings and stress testing to ensure stability. I did not yet have time to make it stable at 3600MHz, but in the future I will update this confirming that it is possible or at least knowing it isnt.... anyway we will be wiser.I hope I helped someone with this. Have a great day.

https://prnt.sc/t1eu1p

edit: forgot to mention... It wont work out of the box tho. If you are planning on going such route you have to pick a motherboard with BIOS FLASHBACK feature. Motherboards that allow BIOS update without cpu installed.