The problem I have with this logic is that the only difference between what you are describing here in 4th edition vs 5th edition is that instead of giving us a clean set of revised corebooks, 4e did it through erratta and stealth updates and wasn't considered a new version of the game.
4e changed... the monster math, the math around skill challenges, how stealth as a whole worked, as well as numerous individual powers and feats...yet at no point did anyone claim it was a new version of 4e or a new edition.
Well I agree that patches like this does not make a new edition, but to be fair, the math changes in 5.5 are just WAY bigger than what 4e had even with essentials. (Just because the original 5E math was sooo much broken).
People talk all the time about how "monster math in 4E was broken before MM3" well the changes were A LOT smaller than what 5.5 did.
- Encounter math stayed in 4E the same. (Ok there was some recommendation for using 5/6 minions instead of 4 for a normal enemy on level 11/21 later)
- Monsters had their damage increased by 10-24% by level 11 to 30. This, however, only did make up for the increased defenses players got (over feats and masterwork armor) because players complaint that monster hit scales faster than player defenses
- (and monsters below level 10 inconistent and some also had a similar damage increase, but not all, it was overall just made more consistent).
- In the same time Monster HP was DECREASED by 10-24% by level 11 to 30
- Soldiers lost their +2 to hit and brutes lost their -2 to hit
So the change was mostly 10-24% more damage for 10-24% less health. So Monster gained something relative small and lost something relative small.
Now in 5.5 correcting the encounter math of 5:
- Monster multipyer for encounter building was cut, this means that an average encounter (3-5 enemies) has 100% more XP budget. (While many enemy encounters even more)
- Similarily for high level encounters the budget was increased ADDITIONALLY
- Then many Monsters of a bit higher level have often 50% more HP
- And the monsters also have more Damage
This is overall something like a 200% more extreme change than 4E had.
I still think its silly to call a balance patch a new edition/new game, but its definitly a huge difference percentage wise in how much 5.5 had to correct 5E vs how much 4E corrected the monster math. Still its just a balance patch. And computer games which released in a broken state had similar extreme patches. (Gothic 3, Vampire the masqerade and others).
It seems to me that the balance of 5.5 is just more balanced, while weighted a little higher. If a 5e character could swing between 1 and 10 (with 1 being totally unoptimized & 10 being fully jacked) then 5.5 is the same, just going from 5 to 8. If you're used to playing all 3's and 4's, then 5.5 seems "OMG OP". But for those who saw a lot of 6's and 7's... well, it looks pretty much the same.
And I am very happy to have not seen any 9s or 10s since I started playing 5.5. YMMV.
This 100% 5.5 increased the power level of the floor of characters mostly, while also cutting many things of optimized builds (power ceiling). This is also why martials were more buffed, while extreme feats removed and wizard only slightly buffed while many overly strong wizard spells heavily nerfed.
This is also why there is no "balance change" between 5.5 and 5. The balance in 5 was just completly broken and 5.5 tries to fix it and part of this is make the extreme builds less extreme, such that you know the power levels of characters better (being around 6/10) and then you can balance the encounters for this more realistic 6/10 and not have to balance them for the 2/10 which 5.0 did, because in the end most people where not playing them anyway.