Honestly? I bet the number is in the hundreds of units total.
Most people do not care that a software package they don’t use and possibly never heard of before today no longer has a free tier on Linux.
And the reason pretty much always came down to good integration between various open source software and proprietary CUDA drivers. And the assumption is that this support will continue for many years.
So, yeah, burning their existing FPGA users is a strong signal never to invest real money in their GPUs for compute workloads.
Not many I would guess.