As long as they don't get rid of them all at the same time I don't think they'll see much, its kept variable enough with the different directors and the small cameo's so while there are a LOT of films with differing characters I think they'll pull it off, I think the problem that they'll have will come from the Disney merger, cancellation of the established Netflix characters and things being moved around for the pending arrival of streaming services will damage the "universe" more than characters being killed off..
That said its a huge money train and I'm sure they'll be profitable for a ling time yet...
Considering that in August 2009, The Walt Disney Company announced a deal to acquire Marvel Entertainment for $4.24 billion and they've owned Marvel Studios since December 31st 2009 every film since 2010 has added to Disney's bank balance.
1 Avengers: Infinity War BV $2,048.4 2018
2 Marvel's The Avengers BV $1,518.8 2012
3 Avengers: Age of Ultron BV $1,405.4 2015
4 Black Panther BV $1,346.9 2018
5 Iron Man 3 BV $1,214.8 2013
6 Captain America: Civil War BV $1,153.3 2016
7 Captain Marvel BV $1,038.8 2019
8 Spider-Man: Homecoming Sony $880.2 2017 (shared with Sony)
9 Guardians of the Galaxy Vol. 2 BV $863.8 2017
10 Thor: Ragnarok BV $854.0 2017
11 Guardians of the Galaxy BV $773.3 2014
12 Captain America: The Winter Soldier BV $714.3 2014
13 Doctor Strange BV $677.7 $232.6 2016
14 Thor: The Dark World BV $644.6 2013
15 Iron Man 2 Par. $623.9 2010
16 Ant-Man and the Wasp BV $622.7 2018
17 Iron Man Par. $585.2 2008
18 Ant-Man BV $519.3 2015
19 Thor Par. $449.3 2011
20 Captain America: The First Avenger Par. $370.6 2011
21 The Incredible Hulk Uni. $263.4 2008
Unadjusted figures, but everything on the list with the exception of The Incredible Hulk, Thor, Iron Man and Spider-Man have all been Disney's cash cow. £18.5 BILLION DOLLARS. That's a lot of cashola, even discounting Homecoming and Chinese income. For £4.24Bn outlay.