One of the Devs said somewhere you can play it for 2 months, so that suggests it's leaving when FS drops. From bungies view its been made to help people prepare for final shape, easy route to 1810, red border drops you're missing, n a few other bits. It'll very likely return or in a new variation, but yeah it appears it's leaving in June along with the usual seasonal content.

That reply seems heavily influenced by current leaks on what this was supposed to be. I doubt it's true unless we are getting things like craftable hung jury and craftable recluse (it's a possibility). I watched the full stream and didn't hear this mentioned. If you have a link to your source for when this was said, that would be helpful. Don't get me wrong, I do think whatever story based activity with the taken as mentioned in the stream will be removed with the final shape. But judging by the information in the stream, it seems like this is something that will stick after final shape and not just it being a way to get read borders, much less the cope that would be farmable deepsights.