Update: After using the solution described below, I realized there's an option in Advanced preference section, "Selection Hotkeys", that can be set to "Restore previous clipboard item"; this is the simpler way to solve the issue.
@dfay Didn't get a chance to look further into this until now, but your solution does work, thank you so much.
The issue with my original workflow setup seems to be that the Hotkey object type with Argument set to "Selection in macOS" will cause that selection to be copied to the clipboard. I've also been able to adapt the script as follows to use Hotkey (Argument set to None) to trigger script to get selection and then Browse in Alfred. Thanks again!
on alfred_script(q)
tell application "Finder"
set sel to selection
if sel is not {} then
set filepath to POSIX path of (item 1 of sel as text)
end if
end tell
end alfred_script