We keep encountering situations like this where a new chemical compound was introduced, becomes ubiquitous in our diets or environments and only later do we find out "Oops, it has serious health or environmental consequences."
It is worth the cost of slower introduction of new materials to take the time to ensure that those materials are safe. We're still paying the cost of introducing lead into our environment in a myriad of subtle ways. We still don't fully understand what the cost of the introduction of microplastics or PFAS is going to be. And regardless of the whether this particular study holds up under replication it is looking increasingly likely that aspartame is not something we should be consuming.
And what's most frustrating is that the people who profited most from these compounds never pay for the damage they cause to generations.
There was huge controversy over aspertame (discovered 1965, limited approval in 1983) in the first decade even though the only solid case against it was that it is bad for a handful of people who have the genetic defect PKU.
Sucralose was discovered in 1976 and wasn't approved in the US until 1998.
The strangest case is Stevia which, since it is a natural product, has gotten into heavy use without really being approved as a food additive. (Loose Stevia rebaudiana leaves make a nice sweet tea combined with Camellia sinensis I'll grant that.)
(2) If you were trying to psychologically manipulate people, "autism" is the threat you would use.