This is actually a common issue that comes up somewhat often… 
There is some risk to loading up random “Breakthrough” workouts, but we all get curious/ambitious from time to time. 
The usual lesson here is that just because you can knock out that really hard workout doesn’t mean that you should. Additionally, it doesn’t mean that you should base all of your future training on that workout either. Since you’ve completed that workout Adaptive Training is referencing that workout when considering your upcoming training schedule. In some cases, this might be good, but in others, it could be a recipe for disaster.
Luckily, you can easily remove any completed workout from your PLs, TSS, AI FTP Detection, and cycling records when you feel the need. Simply right-click on that activity and select, “Edit Workout.” From there you can choose to remove that workout from your Progression Levels which should encourage Adaptive Training to forget that you’ve completed it.
Many times we are able to push through and put in a really hard effort which is great, but similar to racing, these aren’t the types of efforts we can or should be doing week after week if sustainably getting faster is our #1 goal. This is why A races need to be at least 8 weeks apart.
I’d recommend removing this effort from your PLs and continuing on training. If your prescribed Threshold workouts don’t feel challenging enough, you could always use Workout Alternates to pick a slightly harder workout, but I’d stay away from Breakthrough workouts most of the time. 