Upgrade Whonix Gateway

I was wondering, how can I update only the whonix GATEWAY version without resorting to the installer?

in the “download” section there is no longer the possibility to download the workstation part and the gateway.

Yes.

No functionality was lost. Only one of two VMs can be important selectively.

I would like to download only the whonix gateway, isn’t it possible anymore?

Download, no.
Only import Gateway, yes.