I'm a bit confused by your question. You seem to imply SpywareBlaster is just for IE and W7/W8.1. Its not. System Requirement include W10 and as seen
here, it also works with a host of other browsers.
With that in mind, I don't see why it will go away just because support for IE and W7/W8.1 support goes away.
That said, I personally never found SB worth the resources it used on my systems, even when IE was my browser of choice (which it was for many years and until W10 came out).
So, if SB goes away, I think it will be because of a lack of usefulness in general, not because IE goes away.