Well, with just cycleway=track
you do not know is it oneway or not either. So to specify it you would need some weird extra tag anyway.
As far as I know, if you have alone cycleway=track
or alone cycleway:right=track
and no other cycleway info you need to make the same guesses is it oneway or not.
Thanks to Any tags you like - OpenStreetMap Wiki you are free to put cycleway=track
even if it would be deprecated.
Would you be still against describing cycleway=track
as “better replaced by more specific tagging”?
(personally I have no strong feelings about cycleway
vs cycleway:both
but I treat cycleway=track
and cycleway:*=track
as calls to replace it by separately mapped geometries, at least in my region)