I agree most of those guys should be replaceable.
One thing is for damn sure, it's nice to actually have some speed in the wr core.
If they were TCF, they wouldn't have been signed during this period. Cole is a top Sts guy worthy of a DI in that role alone. Hubert is an excellent end AR Canadian who can contribute on a bunch of teams units and rotate actively on the defense, both inside and out. Especially on running downs. Garbutt is a fringe starter in the CFL who picked it up really well late. TCF don't start in the previous GC. Fox has played in the league on 2 teams in 3 years. He struggled with injuries, but that isn't TCF. That is an incredibly talented guy who hasn't been able to translate yet.
Training Camp Fodder, as in cannon fodder, is just a body for your actual players to hit. When a guy has significant upside, that isn't TCF. Thats a developmental guy. Everyone on that list has the upside to start in the CFL. At worst, they are low risk high reward guys.