MG_ Does it actually have a series of pins that are wired into the FPGA core, so you can integrate multiple communication interfaces?
My babelfish still is under-caffeinated, so I might not (yet) understand the question completely.
A FPGA is like a breadboard in a chip. You can load a configuration into it, that defines like which schematics it shall behave. One typically looks at it like logic gates and some custom "blocks" for special tasks, but lots of them is logic represented as look up tables. Depending on the chip there are different amounts of pins to the outside. Probably most FPGAs now are BGA chips which are the apex of mean for the hobbyist solderer, but as long as one only buys complete boards, that won't even matter. So yes, whatever you mean with communication interfaces, it probably can be turned into a bitstream that's pushed into the FPGA and communicate with the outside through the pins you defined.
I'm mentioning iCE40 chips and their toolchain because they were the first ones that got understood well enough to build a free toolchain and their boards are on the low end of the impact to the hobby budget. A system that can rebuild itself from schematics (hardware) to installed OS completely with all toolchains for FPGA and compilers for the CPUs in the FPGA is doable. The breakthrough would be the combination of doing this with only open software and for a hobby budget. Some of these chips even are solderable for hobbyists and if using multiple of them instead of one huge FPGA, such a "digital amoeba"(?) could regenerate components independently, maybe even without reboots in some cases.
Some small but nevertheless impressive FPGA examples can be seen in your browser:
Wow! It can use Silice now too? Last time I looked at it, only Verilog was supported. Silice looks more familiar to most coders than Verilog:
So repeating my thought from above: Not all IT now is operating systems on locked down hardware and apps jailed in emulators for incapacitated users. There are some exciting things showing up on the horizon.