... instead of the 50 or so they'll have had at some point this calendar year 2019,

Which existing ongoing titles would stay?
Which existing ongoing titles would go?
Which new ongoing titles might get a shot?

Me, not knowing enough about Marvel as a whole, would venture these guesses anyway, based on the idea that anyone not getting an ongoing would still get various mini and maxi- series (and yes, the MCU is a definite factor here):

01. The Amazing Spider-Man
02. The Incredible Hulk
03. Captain America
04. The Invincible Iron Man
05. The Mighty Thor
06. The Avengers
07. The Uncanny X-Men
08. The Fantastic Four
09. Wolverine
10. Deadpool
11. Doctor Strange
12. Black Panther
13. Captain Marvel
14. Daredevil
15. Silver Surfer and the Guardians of the Galaxy
16. Marvel Comics Weekly (anthology series for characters not regularly appearing in the other 15 titles)

That's my 16 ongoing titles for Marvel. Tried to cover as many corners of the MU as possible. Hard to see a time where Peter Parker has only one ongoing title, tho.

What are yours? And how realistic would that selection be?