In the wake of Microsoft's rather underwhelming 'pre-E3 event', probably the most interesting thing was the name of the new Halo - Halo 5: Guardians. What's interesting about this to me is that it's the first mainline Halo game to be also have a subtitle, which got me thinking about other games that came out in the last year or so, and it's made me realise that we seem to be leaving numbered sequels behind. Looking at some games that have been released since January 2013, I compiled an interesting list of games that have been subtitled that at one time or another would've probably just been given a number.

Sly Cooper: Thieves in Time (As opposed to Sly 4)

God of War: Ascension (This one, and the one afterwards, you can understand more as they aren't generally considered mainline games, but still...)

Gears of War: Judgement (see above)

Disgaea D2

Assassin's Creed IV: Black Flag (Similar to Halo in the sense that it's the first mainline game to carry a subtitle)

Killzone: Shadow Fall (Why not Killzone 4?)

Donkey Kong Country: Tropical Freeze (Could've been DKCR2?)

Infamous: Second Son (Stated it was to seperate from original protagonist, Cole, but games often change protagonist, so surely could've been a numbered sequel?)

Deception IV: Blood Ties (Why the subtitle?)

Then coming up we have Assassin's Creeed Unity (most likely a working title, but you never know...)

And there are rumours that the next Uncharted won't be called Uncharted 4... etc.

Of course, there seem to be reasons behind a lot of them, but it's just interesting to note a shift in the way companies are naming their products. 

Since its a new gen, the indirect numbering makes them look like new ips, to the average consumer and not continuations.

The second mainline Halo with a subtitle actually. Combat Evolved still exists remember? That aside, it's still called Halo 5, and a lot of the titles you listed are just spin offs.

So no. Numbered sequels aren't going away

If they get rid of the numbering system then they better not just put the first name of the series cause I hate that!

For example, Halo 5 better not be called Halo or Uncharted 4 better not be called Uncharted and etc... It makes googling really hard and the new hipster generation will get confused

This is what I'm thinking it most likely is. The odd thing is though that, generally speaking (of course there are exceptions) numbered sequels will sell better as they are seen as a 'proper installment'.

Oh yep, true true, had forgotten that.

Mario Kart 8

Final Fantasy XV

A series that went the opposite way as use to be Super, 64, Double Dash, Super Circuit, DS, Wii and then said...screw it, 7 and 8.

Kingdom Hearts III