Ocon i think will now take a year out and be the reserve driver for Mercedes AMG, he will get seat time in all the team and tyre tests i think, reason for this will be unveiled in 2020 when Bottas will be moved over for Ocon.
At Ferrari, they need simulator, development and reserve drivers, Seemingly at most races the guy in the sim is Davide Rigon with Vergne and Kvjat in there when he can't do it. Similar to McLaren having Oliver Turvey do most races with others stepping in, and Red Bull running Da Costa and one or two of their old drivers and STR running with Liuzzi as on of their sim drivers. Mercedes have Anthony Davidson, Esteban Guiteriez and Sam Bird. Williams have Alex Lynn and Christian Klien as two of theirs and Renault use Oliver Rowland in their pool. This is a area that Haas and Sauber lack as they don't have a active simulator in their factories, Sauber will have one for next year as theirs is being built at the moment by McLaren i heard (but could be wrong) and Haas don't have the space for one, but are looking at a "Sim Unit" in Banbury somewhere close to their factory to get one. Both Sauber and Haas use the Ferrari sim in Marenello, even STR have a sim, but theirs will be upgraded in the coming year as Stroll and Son are looking to buy land around their Silverstone factory to expand their teams capability.
Ferrari would do well with Vandoorne, but i just wonder if he has been told by McLaren he has till a certain time to get a drive elsewhere or he can be their reserve driver. The reason for this the FIA now need each team to have a reserve driver in case theres a Felipe Massa/Hungary 2017 situation again where Di Resta stepped in. Each team has to have a reserve driver and a alternative driver.
I think Pascal Wheirlien will be at Toro Rosso, however they would regress if they took Kvjat i think, Hartley may not be fast enough any longer, but i think they are looking at a list of drivers, Buemi is out, Vergne and Vandoorne are two under consideration.
Haas will confirm continuity soon.
Sauber will boot Ericson as he has been embarrassed this year, i think Giovinazzi will be in for 2019.
Williams will be Kubica and Russell as i think Toto wants Williams to take George for cheap engines, and Kubica i think will get his fairy tail and come back to F1 as he has impressed in FP1 outings and all team and tyre tests.
F1 2019 will see the largest driver moves since 2010 i think.