No. Do not attempt to mount a new GE switch into an old strap.
The new switches are larger and thicker than the old ones, and you will likely damage the switch if you attempt to wedge one into an old bracket or over-tighten an old wall plate down on top of it.
The pressure from the too-small strap or a tightly mounted cover plate will constrict the switch housing, likely causing the buttons to bind or stick and potentially burn out the relay.
For safe replacement parts, buy new low voltage GE switches or the new low voltage light switch covers that fit them properly.