Correct, Men meet Elves in the first episode of Season 5. Teasing the content for the next season is part of the job of a Season Finale, though. Men do exist and are on the move at this point in time.
Yes, if you will recall, they walked back the language 'overconfident' during the session, and instead decided that Fingolfin would focus on pride in what they have accomplished with the Siege, and hope for the future of the Noldor in Beleriand. Being hopeful that the Watchful Peace can continue is not the same thing as being overconfident or underestimating Morgoth. Sure *we* know the Siege is going to fail, so any hope or trust or faith in it will ultimately prove false. But that doesn't have to mean that anyone with any hope is being overconfident and brash. They requested a Fingolfin who would trust in the Noldor's preparations and watchfulness, rather than be in any way dismissive of their enemy. Fingon is in agreement with him throughout Season 4, but begins to doubt they can succeed in Season 5.
Also...the Siege continues for 400 years. Fingolfin is the military commander of all the Noldor (as High King) throughout that time. So, 'SIEGE' has to be his plan (the plan that he supports) because...that is what they do. If Fingolfin says, 'hey guys, let's attack Morgoth!' and everyone's response is 'eh, I'm not really feeling that; can we take a raincheck?' it means that we're portraying the High King as someone who does not have the authority or ability to make that happen. But, somehow, Fingon does a bit later? So, it causes problems if we have Fingolfin pushing for War with Morgoth and the other Noldor dismissing him. There's no reason we couldn't have Fingolfin feel out everyone, and dismiss the idea of war himself because everyone seems pretty content with the peacetime arrangements created by the Siege. But to have him push for war and be shot down? I don't see how we can make that work.
Also...under what circumstances is Maedhros going to be totally cool with continuing an indefinite siege and show no interest in attacking Morgoth? The Fëanorean approach to coming to Middle-earth has always been, first and foremost, fight Morgoth. And as long as Morgoth holds the silmarils, they are Oath-bound to fight him. So, if Fingolfin were to suggest an attack on Angband...what reason would Maedhros have to say no? Would he argue that they aren't strong enough? Waiting isn't going to change that (elf reproduction rates being what they are). We had Maedhros pushing Fingolfin to go to war with Morgoth in Episode 3; when Fingolfin turned down that suggestion, Maedhros settled for moving his group to the east and helping to fortify Beleriand. We can't just...forget that conversation happened.
Also, at the end of the day, who would you propose express confidence in the continuing Siege if not Fingolfin? *Someone* has to think this is going to work, and say so on screen. Thingol's not an option; he's trusting in the Girdle of Melian, not his kinslaying Noldor neighbors. Turgon and Finrod aren't options; they got unsettling dreams from Ulmo and set out to build safe havens against the possibility of the Siege breaking. Aredhel chooses to go to Gondolin, so she's out (same with Idril). That leaves the Fëanoreans, Aegnor, Galadriel, Fingolfin, Fingon, and Círdan as your options. Do you see a better choice than Fingolfin on that list?