Mario + Rabbids sold Well passed 2 millions at this point and we still have no official numbers from Ubisoft.

I gotta say i'm surprised by this comment.

Given the sales numbers (vgchartz's) either he exaggerated or their expectations were really, really low for some games.
For example, Doom, which released pretty at the same time as Sonic Forces, sits at 351.783 units, whereas SF sits at 618.334 units. This is Doom vs a critically panned title...
Also, WF2: TNC, is, in it's 3rd week, selling a third of what Doom sold in the same time frame.

I really can't comprehend how ALL games were "hugely popular".

 Doom released a year after it launched on PlayStation and Xbox. Sonic forces launched at the same time on all systems. I don't think that's a good comparison.

I think that if we read between the lines here, and apply some logic, what we really learn is that  Bethesdas porting costs are low.  

Being a late port didn't stop Skyrim from doing way, way better than Doom. Therefore i think comparing Doom with Sonic Force (a game praised and really poplular vs a overlooked and really criticized) is more than fair.

I don't think he was talking about revenue and or profits, but actual sales volume.

It is also good to remember that a game like Sonic Forces, besides the fact it launched hand-by-hand with other versions, wasn't sold at full price and had gone some massive sales both on retail and eShop since it's launch while Doom is full price since launch day.

Popular can mean a lot of things, you know. The announcement of DOOM Eternal for Switch generated a lot of buzz, for instance, but, at the same time, there's no denying that both Nintendo and Bethesda have built a decent base for the former's games on Switch.

Well, Skyrim is almost certainly over a million already, and while Doom's numbers may not be chart-scorching, it should be remembered that porting an existing game is a hell of a lot cheaper than making one from scratch. 

It's common on forums to act as though everything under a million is a flop, but Doom's Switch port may only have needed, say, 200k to turn a profit, with everything beyond that being gravy. Since these ports are being handled by external dedicated porting houses (Panic Button/Iron Galaxy) it's not like they're tying down significant resources at Bethesda, so they make a profit with little risk or investment, the middlemen get to make a tidy living, and Switch owners get more games. Everybody wins.

The simple fact that Doom Eternal is coming at all suggests their efforts thus far have born fruit, if not they would have abandoned the platform by now.

I don't think Bethesda shares numbers for anything actually.

VGChartz could also be wrong too though...

I don’t know. Whenever I hear someone use the word “hugely” my BULLSHIT meter goes off the scales!

Glad to see they are happy with their games sales.