No, that's not correct. Apple has never stated what "Max" means and the Pro Max has never just been bigger display size -The entire device is bigger so you also get a bigger battery with the best batterlife in a given line-up.That would make sense if they didn't offer a "regular" iPhone 14 "Plus" that had the same screen size as the iPhone 14 Pro "Max", since the last word of those two names refers only to the display size, not any other features. It makes sense with the iPhone 13, because the "Max" is indeed the biggest phone in the 13 lineup. The "Pro" in the name is what differentiates the other features in marketing.
Additionally, while the 6.7 iPhone 14 Plus might get the exact same display size as the 14 Pro Max, the quality and brightness of the 14 Plus' display will be less than the 14 Pro Max. And the 14s Pro are also going to be at least same 120hz displays like 13s Pro got.
If display quality was the same across all four models then I'd agree. But it's not and the all the other features of the 14 Plus are not "Pro" nor the "Max"imum you can get.
So "14 Plus" makes the most sense.