343 is trying to distance themselves from having "clone weapons" in Infinite, that's to say they want every weapon to have a unique place in the game's sandbox.
The Brute Plasma Rifle and Spiker were two of the most aggregious weapon clones in the series. However that said, I think based on what we've seen of Infinite's sandbox so far, there is room for them. The BPR could be the Banished's close-range spray-and-play plasma weapon, since so far all we've seen of the Plasma side of things is a mid-ranged utility/plasma hybrid, a heavy splash-damage based weapon, and the Plasma Pistol. While the Spiker could be re-tuned and turned into a low rate of fire, but very high-power if accurately used headshot-based automatic. (I'm thinking like the Hammerburst in Gears 2/3, or the Needle Rifle with TU/Zero Bloom settings but firing a projectile that requires leading your shot).