I have found slight tilt in early bridges, virtually none in the hollowed out 60s version, but in either case nothing like the Evertilt. If anything it is a lack of consistency in the casting of the "hook" that causes that on the earlier version. The Evertilt is a poor design from the un-clampable stud mounts on down. Terrible flaw right there, but the whole thing reeks of rushing. And yes, the 50s nickel bridges are massive. You could kill an Elk with them things. Good sidearm delivery. And nylon saddles suck sustain, by their nature. Hard brass,nickel or steel are much denser and harder materials to use for string saddles to transfer tone and sustain. And more expensive, which was probably Gibson's motivation.
And the MusicMan bridge mounting was Mr Fender at work, and just a recognition of the superior mounting of two honking studs vs five little wood screws. If Gibson had used those screws, it would have been much easier, stable, and comfortable.