Before Fastlane, there were genuine worries that WWE might pollute the title scene by forcing John Cena into the WrestleMania mix. To a lesser extent, there were also (slightly irrational, in retrospect) fears Cena might become WWE Champion, if only so he could crow about being the first ever 17-time champ in company history.
As things stand, none of that is happening and WWE have stood by AJ Styles.
Styles will go on to meet Shinsuke Nakamura at 'Mania and lord only knows what WWE have in mind for Cena. If they rush, and assuming 'Taker is healthy enough, there's still time to set up that dream match with big John.
The key word there is rush. As a pay-per-view, Fastlane in general felt a bit cobbled together, and more like a souped-up house show card than a proper must-see special. Still, despite the hasty feel of it all, the show did let SmackDown's creative team prove they're capable of getting key decisions right...