That's quite weird, but I can tell you that it's actually happened even before the Reforged had gone gold (or before January 28th, 2020).
On the very latest patch of Classic Warcraft III (1.31.1), this infamous bug still exists during the single-player campaign:
Hello, The recent updates for Warcraft 3 broke the game. Please help notify the “Blizzard classic games developers” about the bugs: Thrall’s items can be seen dropped on ground in a cutscene with Medivh near human ships in prologue. When Medivh meets Arthas on the road in the cutscene...
us.forums.blizzard.com
Notable game strings-related bug I've found on this thread:
1.In Rexxar campaign, some units did not have their name or have a weird name like "P" when you select them.
2.When you point on the Unstable Concoctions during Infiltrate Theramore Quest, it mistakenly says "Centaur Marauder" or something similar.
3.The (null) strings also appears in Shaman's name when he's about to say "Storm, Earth, and Fire. Heed my call!" during the TFT Credits. The same thing also happened during the Thunder Ridge Quest (on the 2nd visit with playable Drek'Thar), after discovering the Human Lumber Mill.
Of course, not only the empty or broken strings you might encounter on the latest patches, but you might also encounter the other bugs. I heard that on the Night Elf 2nd Mission, there were bug reports about missing hero inventory on Tyrande or something similar. It's still present in Reforged.