Sainz got so lucky that Toro Rosso wanted to terminate that engine contract and could use him as a bargaining chip, otherwise he would've been stuck there.
On a related note, former voice of Finnish F1 Oskari Saari (moved on to new things after last season, he was a commentator for like 13 or 14 years) said on his podcast that he heard from a pretty reliable source that the Kvyat/Gasly swap rumour from last year (right around this time of the year IIRC), wasn't just a rumour. It would've actually happened had Gasly kept his mouth shut about it.
Renault told Red Bull they want to terminate contract from end of next season
Decision casts doubt on the future of Max Verstappen and Daniel Ricciardo
Renault will enter into a new affiliation with McLaren for future seasons
Read more:
http://www.dailymail.co.uk/sport/fo...erminate-contract-Red-Bull.html#ixzz4seh5cc6s
Does it really though? There's only a few spots to go around and the most dominant drivers (Hamilton/Vettel) have a say in who their teammate is. Ferrari is Vettel's team as long as he's there and he's shown throughout his career that he wants to be the clear cut number 1. Mercedes same thing with Hamilton, the debacles between him and Rosberg probably have made them more aware of who to put in the other car. IMO Hamilton doesn't have as much say as Vettel does, but he surely has some power.
Ricciardo to Mercedes? I could see that happen, although I think Mercedes is holding out for Vettel (in that case Hamilton goes to Ferrari, as he's dreamed of) and won't commit to anyone long-term.
Ricciardo to Ferrari? No chance as long as Vettel is there.
Verstappen to either team? No chance as long as Vettel/Hamilton are there.
It would be pretty interesting if both drivers left RB, that who would drive for the main team? They don't really have anyone with a wow factor within the RB development program right now and the bridge with Sainz is burned.
Mercedes: Vettel/Ocon
Ferrari: Hamilton/Leclerc
Red Bull: Ricciardo/? (Bottas maybe, if they don't have a good enough young guy by that point?)
Renault: Hulkenberg/Sainz
McLaren: Verstappen/Vandoorne (McLaren has been a big team in the past, probably Max's best bet for a competitive car outside the big 3 until one of Hamilton/Vettel retires)
Retired: Raikkonen, Alonso & Massa
My guess for 2019.