Good joke man
(Funny enough MM is not "that" big of an player in Modern NBL, which is quite surprising, when you think about how broken that card is).
Regarding DTT and what influence it will have:
There are three primary winners, and a lot of secondary ones. Primary ones are obvious Jeskai Ascendency (the UWR Tempo/Combo version), RUG Scapeshift (the secretly "best" deck in the TC/DTT area, since it had both a good Delver as Pod match-up) and Control (especially Esper Control would love that card). For the secondary ones only Delver decks have to get noticed, since it would allow the deck to be a solid Tier 2 deck, even though it struggles with a lot of things.
Jeskai Ascendency was a good deck, especially since it was not an all in combo deck + played a relative high amount of interaction (6-8 removal spells and 4-6 counters). The earliest win was on turn 3 thanks to Probe, which is now no longer possible. Hence, the earliest kill would be a turn 4 kill which is more than okay (Modern is a turn 4 format), especially since you can interact quite easily with the combo elements (Bolt/Path vs Fatesticher, Decay/Remand vs Ascendency). Would develop into a solid Tier 2 deck, sometimes dipping into the Tier 1 scene, when the Meta is soft to it, sometimes going down to Tier 3.
RUG Scapeshift would be the real winner. Everybody who followed the deck back in the DTT times knew, how good it was. However, the main reason, why it was so good was mainly of how the interaction from the deck aligned with the current meta. Anger was MVP (both against Delver as Pod), especially when you were able to cast it on turn 3 with counter back up. It still had a decent clock and the goldfish with a perfect draw was at turn 4 (needs a perfect hand and you cannot play anything else but ramp spells basically). Again, no problem with the Turn 4 rule. However, what the deck CAN do is, that when correctly build it can offer a decent choice against both big mana decks (as long as they do not sling Caverns and Ulamogs at you) due to the counter suite and have a decent match-up vs midrange esque decks. However, on the other side the control (lots of air) and aggro (again lots of air) match-ups are not great, this is especially true in the current RUG version. Hence, would establish as a solid Tier 1.5, sometimes dipping down to Tier 2 when there is more aggro and control and being at Tier 1 when there are more targets for multifunctional interaction spells (like Anger back in the days).
Last but not least Control. I can only speak from my personal experience with UW Control back with DTT, have not played Jeskai or Esper Control with that card, so if somebody, who has played with DTT in the respective deck, can correct me if I'm wrong, please go ahead.
In UW Control Dig was a okay-ish card. The problem was, that filling up the Graveyard was an actual problem. Due to the nature of the deck of playing more board based interaction spells (Wall of Omens, Detention Sphere, Vedillion Clique, Runed Halo,...) and the low number of Fetchlands (5 is the max you usually want to run) you had problems to get a "early" Dig off. Most of the times Turn 4 was a realistic Dig for 4 mana turn, which was nice but not close to game breaking. Hence, you had to build the UW Control deck still with the early game in mind hand had the Digs as a late game tutor for the silver win con bullets (be it WSZ or Rev in the more draw and go version or the Planeswalkers in the more tapout version).
However, Dig would improve both Esper and Jeskai a great deal and would give them a real shot of beating things like the ramp decks or something like Cavern of Souls.
Overall, while Dig is a broken good card (as most of the modern powerhouses) it would be INTERESTING to have it in the current Modern format and look, how it would develop from there. I honestly doubt, it would result into huge problems, it would just force a shift in the comfort levels from the players.
PS: And totally agree, MM3 is absolutely bonkers ^^