While this may be true in the short/medium term, but in the long term FPGA may end replacing GPUs, as the costs go down and other players comes in and we see more mining oriented FPGAs. This is just the genesis of public FPGA mining.
Exceptions would be ASIC alog coins or coins who's Devs want to be FPGA-resistant (at least they think they can be FPGA-resistant).
There are 3 threads, where fpga devs are selling(or incite to buy) this devices
today.
Most of those algos were FPGA and ASIC resistant in past(like scrypt, x11,x13, quark, etc). But coin devs trying to make fpga-resistant and asic resistant algos. They will increase memory size and bandwidth requirements and make new resistant(today resistant, not tomorrow) algos, like mtp, equihash(with different parameters), phi2, etc.