RE: Recentish C-s M-y change

[Drew Adams]

> Maybe then on every use of old command we could display a message

Please don't.  Not by default anyway.

> that will suggest to use a better keybinding 'C-y'

One person's "better" is another's "worse".

> because to hold the Control key, then type 's' and 'y' is easier

There are reasons for, and reasons not for.

> Then later we could bind the new command to 'M-y' again.

Why later?  You want to make a default key change,
with a suggestion that maybe-later-we-could change
it back?