"Don't worry, mods will fix it" has always been a bullshit "comfort argument", anyway. 1- There's no guarantee it will happen. 2- IF it happens not having full access to game code and dev tools limits strongly how well modders can make it work. 3- It's bound to be a sub-optimal, unpolished experience prone to bugs and UI limitations compared to something that a developer addresses dirctectly.
Also, for the people who were worrying about "having to redo everything from scratch", Swen has been on record openly stating that they already have the UI in place to scale up to six men, they just weren't confident on the idea to make it the default mode (never mentioned before because it's a video interview he made during a streaming that I never watched until few hours ago), so there's that too. Let's hope this amount of feedback in favor of six will serve to give their "confidence" about this a boost.
And if anything, let 4-men party as the default for console players. AS people who never played a CRPG with a good control scheme, they may even be able to appreciate it the most.
You can already achieve a party of 5 possibly 6 in the tutorial.
If you play 3+ multiplayer and recruit the brain and Lae'zel.