Which isn’t to say that the creative minds in the MCU shouldn’t be cautious with this.
After all, we already have Tony Stark’s B.A.R.F. technology for that, so if time travel is used in Avengers 4, no doubt it will play an integral role in defeating Thanos or whomever is the main antagonist.
So while the MCU would certainly be well within its rights to use time travel in other movies, it should be careful with not only where it should be used, but also the manner in which it’s used.
Whether the Time Stone is the reason for how time travel is possible in Avengers 4 or it’s due to another reason (like Scarlet Witch’s powers reaching House of M levels), one can imagine that it won’t simply be used to re-experience times long past.