The R44 Clipper II is built with pop-out floats, unless you specify fixed floats, (and with additional anti-corrosion protection). The aircraft is EASA certified and mine is used for Public Transport work including over-water routes that require floats.
So I think the answer to the OP is "yes", in the circumstances above.
It would be a totally different question to ask if pop-out floats can be fitted to a non-Clipper aircraft. I don't know the answer to that one.