Things change all the time. A socket today cannot be expected to support a processor from the future. There is no guaranteed lifespan for a socket, as processor design and requirements are constantly changing.
The same with motherboard features. Your firewire of the past has been replaced with USB-C today. VGA and DVI have been replaced with HDMI and DP. CD/DVD have been replaced by USB. ISA slots are long gone, as well as PCI slots. DDR-2. et al, are also gone. PATA replaced by SATA, which is being replaced by NVME.
The point is that you should expect change and obsolesence. It is part of the continiual evolvement process. This is reality. Sorry, but there is no answer to your question.
W10 2004, W10 May 2020, W10 20H1, W10 19041 - A rose, by any other name, still smells.
but this is 1151 socket. I understand Intel has already replaced it with 1200. This means that there will be no new processors for the z390 motherboard. or am I wrong?