I think it is unreasonable to delete it.

Let's say you have 8.0 and 9.0
You will get 9.0 back from the install.

-r--r--r--  1 root  bin  86637176 May 31 10:32 /usr/lib/libLLVM.so.8.0

that's 82MB.

The user's disk is short 82MB?

I doubt this fixes any kind of long term problem, and now is the time for
that user to repartition the disk.  Next month's snapshot is going to blow
through that.  The other library cranks in /usr/lib/lib*.so* are going
to crawl through that in no time at all.