So what is actually stopping this from happening? What are the possible downsides of increasing the block size to 2mb?
Because this "solution" is redundant. SegWit has the same affect in addition to having many more other benefits. Classic is just another attempt at taking over the system.
Bitcoin Classic is using concerning tactics to overtake Core. jtoomim is willing to have consensus threshold be as low as 60% for hard fork. This could lead to dangerous forking situations.
This guy is starting to look like Hearn 2.0, aside from having even less skills. A 60% hard fork would split the network in 2 and possibly cause unrepairable damage. Let's not forget this
"survey" the was done, implying that this was possibly planned before.