Tested with 4.5.0 and
For some reason, the first dialogue in one of Strife's endings that you hear after killing the Entity won't play at all.
(Either the "happy" ending or the "mediocre" ending.)
The death-ending (when you die during the fight) works as normal, however.
To test, run Strife, go to MAP29, summon and kill EntitySecond.
or run this command line:
gzdoom.exe -iwad strife1 +map map29 +summon entitysecond +kill entitysecond