I just don't think it's helpful to assume that because it worked a certain way in a previous edition, it will work that way in this edition.
It's helpful in this case, in 4e it was disastrous. One of the lessons of the edition war: write for your audience.
The rules in this editions books are there to tell you how it works in this edition, you shouldn't need the rules from previous editions for that.
It's not like you have "see page XX of the 1e DMG for how this rule actually works" anywhere in 5e.

But, you do have familiar, natural language instead of carefully-defined jargon. That's ambiguous, and knowledge of how the game's 'always been' sure helps interpret that ambiguity the right way.
...but you already caught that...
Many things in 5e are explicitly written to evoke a sense of 1e and 2e while retaining the flexibility and choice of 3e. But not everything. If the 5e rules are vague...then they are vague. It's up to the DM's preference - and they can certainly use previous editions to inform their decision on how to handle a vague area.
That's my thought. If you know how D&D 'has always been' (except 4e of course) then you can effortlessly navigate many of the vague areas. If not, they can trip you up.
Because many many players and DM's in 5e have never played a previous edition.
I suspect the majority of D&Ders and especially of DMs are drawn from the more-experienced pool, be it long-time or returning. And, it only takes one experienced DM to introduce a half-dozen new players.
Per session.
Besides, 5e was consciously designed for fans of past editions. Even when, in all his playtest-era ramblings, Mike went on about new players, it was always in the context of 'what worked for us when we were new' (as viewed through our rose-colored hindsight), not 'what would work for brand new players, today.'
But enough of being serious about this silly debate. I'd promised myself to stop doing that pages and pages ago.
Who's being serious?