"The OL needs time to gel." Ok. How long does that take?

[RealSNR]

I'm a busy Chiefs fan on the internet, so I need instant and direct answers, please!

I'm as excited about the new OL as everybody else, but I keep hearing this warning from critics, "Ok, but your new OL will need time to gel." Teicher the Dickless even said we could be looking at 1-3 or 0-4 to start the season all because the OL will not have had time to "gel" yet! Seems scary!

I'm trying to think of massive single-offseason OL rebuilds in the past. The recent Cowboys rebuild in the early 2010s was entirely through the draft and took at least two seasons to construct. I think I remember the Chargers doing a full-on rebuild a bit later and being impressed by it, but in typical Chargers fashion is sort of just slowly collapsed and dudes got injured.

Is there a precedent for this kind of thing where we're virtually guaranteed a Week 1 OL full of starters who have never played next to one another in a game? And when they say, "They need time to gel" does that mean a few weeks? Just a game or two? Not until late in the season? And what's the severity of playing with an un-gelled line?