A primary source is going to be very difficult to find unless you contact someone at one of the drum manufacturers and ask why they brought their high tension snares to market. But without a primary source, you can still make observations and deductions, and from that I've pieced together the stuff below:

It had been customary for a number of corps to crank mylar snare heads as tight as the heads could go. Tighter heads can produce a crisper, more articulate sound with shorter decay, allowing details to be more clearly heard.

Remo introduced their Falam (kevlar) head in 1987. It allowed for higher tension than mylar heads, but the problem is that the new heads were able to withstand tensions that the drums themselves couldn't. If you over-cranked a mylar head, the head would give. If you over-cranked a kevlar head, the drum would break. Lug casings could crack or shear, rims could crack, and shells could warp or collapse. A sturdier drum was needed to handle the tension demands of these new kevlar heads, which led the drum companies to come up with new designs.

I don't know the first person to invent/develop a free floating high tension snare drum, but the first company to have one on a drum corps field was Premier. Star of Indiana used Premier free floaters in 1989. The Blue Devils also marched a free floater in 1989, but it was sort of a hybrid. BD had an endorsement deal with Yamaha, who owned Premier at the time. BD had Premier free floaters in 1989, but with a Yamaha snare strainer and Yamaha logo on them. Pearl's free floater hit the field in 1990. From 1990 through 1992, Yamaha's answer to high tension drums was their Corps Custom model. It wasn't a free floater, but had a reinforced shell and heavier-duty lug casings. Around 1993, Yamaha introduced the sfz free floater as their top-of-the-line high tension snare.

Bear Percussion is not around any more, and it's very sad. I used to use their Kevlar bass heads on my rudimental bass and it was quite amazing.