Elements 8 on 64-bit iMacs

There is no need to update pse 8 for mac High Sierra 10.13.4 as pse 8 should continue to work the same as always.

It's not until the next new version of macOS 10.14 or whatever apple calls it that 32 bit applications may or may not work, since apple itself is not clear about the transition timeline.

32-bit app compatibility with macOS High Sierra 10.13.4 - Apple Support

See my comments here:

32-bit software incompatibility

To answer your question, no, as far as i know, adobe will not be issuing updates to make 32 bit applications 64 bit, so you would need to upgrade to latest photoshop elements version, which is 2018 at the time of this post, if and when the macOS stops running 32 bit applications.