When I pulled out the Sidney Bechet Mosaic to play this one was right alongside so I relocated it to the upstairs as well.
This was only available on LP, and it’s a great set in many ways.
“Complete Mosaic Johnny Hodges Sessions 1951-1955” LP 1
The Electrola issue WAS a European issue of the American Victor recording, but not "quick". Not nearly, as this case shows. In fact, it was even later than you and I would have assumed. I would have thought the much later "Cubano Be Cubano Bop" pressing (of an original recorded in late 1947, 22 months after "Night In Tunisia") hit the market relatively quickly in 1948. But not so. Out of curiosity, I checked Discogs for what (numerically) must have been the next Electrola release (EG 7780) after the two Gillespies, and to my amazement this was a German cover version of "Blue Tango" by Leroy Anderson that was a chart topper in the USA in early 1952! So the two Dizzy Gillespie 78s cannot have been released too long before that period. (The Electrola releases AFTER EG 7780 according to Discogs featured unimportant German popular orchestra music that is not likely to figure in any discography and therefore cannot be dated accurately.)
In general, even though the delays of EG 7778 and EG 7779 may be extreme, it is far from so that releases outside the USA always followed the U.S. original release fairly quickly or with fairly regular delays during that period. It depended on the licensing labels, their "response times" or marketing considerations (cashing in on overseas hits etc.).
And yes, the name of the tune had changed by 1945. Since the other surviving early recordings of that tune (various live recordings) that predate the Sarah Vaughn recording of 1944 all were released for the first time MUCH later than 1944/45 it is obvious they were assigned the commonly used title of that tune in hindsight for those later releases.
However, referring to V-Disc 275 of September 1944, the actual V-Disc pressed in 1944 displays the "Night In Tunisia" title:
https://www.discogs.com/release/7805779-Tony-Pastor-And-His-Orchestra-Boyd-Raeburn-And-His-Orchestra-Schicklegrüber-A-Night-In-Tunisia
So my conclusion would be that this title had come into common use by that time - in 1944.
(BTW, just for info, that "Schicklegruber" title refers to the maiden name of the mother of none other than Adolf Hitler! A name often used in mockery when referring to that "person".)