Kante is about to sign for one of the Saudi Arabian teams interested in him. His salary could reach 100m euros according to the source. I don't feel like Chelsea will try to extend his contract. If they had such intention I think they would have started the talks with him already. That lasting injury period must have affected Chelsea's opinion about him negatively.
There oli money doesn't affect the main sport because they can't attract younger players and they're not competing in any top European league so their oil money is only been used as a retirement pension for player that are done playing football. Let look at the players they have been able to sign so far and those they're rumour to be attracting, these are players like Cristiano Ronaldo, Benzema and the rest. This guy's don't have anything more to prove to Europe because they have won basically everything. Now they're interested in Messi and Kante, they have already achieved everything in football too so they don't care about competing anymore.
I think Kante should take the deal and leave for Saudi Arabia. That country will suit him very well because he's a Muslim and also a very loving guy. He shouldn't think of renewing his contract at Chelsea. He's now injury prone, he couldn't play much game last season and that's all because of his injuries. Kante has won everything possible with Chelsea in regards to major trophies so if he retired now by going to play in Saudi Arabia it isn't a bad thing and Chelsea should capitalized on this offer to get a good money for him instead allowing him to run out his contract and becomes a free agent.