You're wrong and you're cherry-picking. Both settings have lots of tech the other doesn't.
Except for the Alderson Drive (and its tramlines)...
FTL tech is the core of any interstellar sci-fi setting. "Traveller" and MiGE have two very different drives.
... all the tech in MIGE is roughly TL 9-12 Traveller tech (TL 12 for the PA turrets).
There are no PAs in MiGE. MiGE's version of personal lasers, the kind that need ammo, can't be built by the RC in TNE without Hiver imports. What does that say about their TL?
The lack of gravitics is a non-issue.
No it isn't and you're cherry-picking again.
... TL 9 Traveller ships also lack AG and IC...
Not in Book 2 or High Guard, the design systems used to create the vast majority of "Traveller" ships.
... are items that can be left out of the design.
They're left out because there weren't any rules from them and not because they aren't present.
Even the fluid tanks are in TNE...
One design system out of 6? Seven?
The MacArthur uses spin-grav, too, in the rare cases of coasting, and when in orbit... just like the Lab Ship.
That's apples and orange and you know it. MacArthur uses spin gravity because it doesn't have gravitics. The Lab Ship uses spin gravity because the gravitics systems aboard can interfere with experiments. One ship has the technology and the other doesn't.
Also, the Alderson Drive looks to have been the direct inspiration for Imperium's jump mechanics - and Imperium is the prototype for the OTU. (That Marc considers Imperium canon is obvious as it's listed as Traveller Game #1 on the CD.) Oh, and the Alderson Drive is in TNE, too...
It says as much in the 1st version of the rules, but Imperium isn't purely OTU. There are lots of differences between the two including tankers which make fuel from stars.
TNE presents all sorts of alternate FTL drives, but that doesn't mean they're used in the OTU.
It's also a setting, one of the few of the era, that has near-constant thrust drives and almost no coasting - excepting only civilian freighters, the CoDo universe is filled with lots of stupidly long accelerations.
Seeing as all the other sci-fi settings have warp drive or something similar, thrust isn't an issue there. The MiGE setting only sees warships and couriers using constant acceleration and the trips are long because of where the Alderson Points are. Sol's is out past Neptune IIRC.
MiGE was an inspiration and not a blueprint. The same as Poul Anderson's League and Flandry stories, the same as Norton's Trader stories, the same as Asimov's work, the same as man other books, and the same as Miller's unpublished game about an interstellar empire surrounded b six enemies.