Here a lot of talk, so let's speculate about next types of enemies.
The game will have 20 types of enemies: 11 xenomorphs and 9 the others. From xenos we already know 9 types and 2 types from the others.
First about xeno. Who are the 2 remaining types? And how are xenomorphs define in this case - in a broad sense or in classical? Is the neomorph (deacon, trilobite or other spawn of black goo) on the list of xeno? Or do they relate to the remaining 9 non-xeno enemies?
Second about the others. We know about working Joe and combat synths. If we assume that the combat synths will be armed with different types of weapons, then I think that they are still one type of enemy. Who will be the last 7? Engineers and black goo's mutants? Or even humans - WY-commando?
I guess that of the two remaining xeno we will get neomorph and something new. I don't think that we will get deacon - I just don't see how it works, moves. Trilobite will be fun, tho. I think that Tusk would be a very cool solution.
And the last 7 non-xeno enemies: Engineers (maybe one type in SJ armor, and one without), human-zombie, some mutants (like hammerpede, but bigger). Who else? Engineers-zombies/mutants, like on concept arts to Alien: Covenant? Or something new for franchise?
It is a pity that we have no place left for the red xenomorphs - maybe in DLC or in another game...