You completely missed my point, which was after the section you emphasized. The issue isn't about not having auto-success and auto-failure, it's that newer DMs are going to have a harder time decided when to have a roll. If the rules say that any roll has a 5% chance of success, players are always going to push for a roll, even if there shouldn't be one. Conversely, some newer DMs are going to think you have a 5% chance to fail at anything, since you'll fail 5% of every check. The second part already took a long time for many to adapt to in 5E, and this is simply going to confuse the matter further.That hasn't changed at all. The DM still only calls for roll if there's a chance of success and a chance of failure. The new auto-success complements that (because why are you even rolling if a natural 1 would still succeed or a natural 20 still fails?)
Note, I won't have any issues if this is the way it is, but I've been running 5E since the last playtest. A brand new DM, however, is limited to what they put in the rules, and WotC hasn't been particularly good at helping new DMs learn how to run a game. They're supposed to be working on this for 1D&D, but this is adding an additional obstacle that I feel is unnecessary.