The multiplayer still shares the same assets, models, textures, physics engine, and other arbitrary game code with the campaign. There is still a lot to download to start the multiplayer portion.
FiOS doesn't have an 85MB/s level, they have a 75MB/s level, which costs $90/month on its own. You also assume you have great throughput to Sony, which is funny, shows how little some people understand what theoretical maximum throughput means. The PS4 will still be limited to a certain number of concurrent connections, not enough to even scratch the surface of the pipe you have. You will get things at around the same pace as someone with much lower bandwidth, as the connection limit will undoubtedly be optimized for the most popular broadband connection level, 15Mbps.
With a larger pipe you can do more at any given time, but it doesn't ensure that you will have a connection to a given server that is any faster (wider) than anyone else. If they are able to increase the number of allowed concurrent connections dynamically it would be faster, but that usually makes the experience worse for those with slower connections, because you are chewing up a big portion of Sony's bandwidth.
I'm a software engineer, I know what speed my internet is and I fully understand throughput:
I just downloaded Uncharted 3 which is exactly 40GB and it took an hour and 15 minutes - you do the math.
