I think you are correct. No facts yet proving there were Phantoms produced for the 1949 model year.
It seems that everyone believes there were actually1949 model Phantoms due to the fact they had a late 4th quarter 1949 serial number. Schwinn's model year changeover usually started with bikes wearing November and later serial numbers, and in some cases slightly earlier than November. The 1950 Phantom apparently had an early release or debut in late 49 for Christmas sales and technically they were not a 1949 model. The earliest real Phantom serial number I've personally come across had a very late October stamping. If anyone has some info that would verify a legitimate 1949 model Phantom please share it.
A couple brand new models that had an early release, and I'm sure there were a few more.
1954 Jaguar ballooner
1957 Jaguar middleweight
AS A TEEN BACK IN THE DAY, I HEARD THAT THE 1949 MODELS CAME OUT IN THE FALL
OF THE YEAR. SO THE BLACK PHANTOM WOULD HAVE COME OUT BY DEC. OF '48 FOR
CHRISTMAS.
AND THE 1950 RED AND GREEN PHANTOMS LIKE WISE CAME OUT IN THE
FALL OF 1949, I HAD A RED PHANTOM SERIAL NUMBER DATED LATE '49, THAT
COULD HAVE COME OUT FOR CHRISTMAS.
I DON'T HAVE THE RED PHANTOM ANYMORE, BUT THE NEW OWNER A CABER
HAS IT AND CAN CONFIRM THE SERIAL NUMBER DATE. ANY ONE WITH AN
EARLY BLACK PHANTOM CAN YOU CHECK OUT THE SERIAL NUMBER.
ANOTHER INTERESTING FACT. THE FIRST PHANTOMS HAD A MESINGER
B-1 STYLE NOT THE DEEP SKIRTED PHANTOM SEAT WE ALL KNOW.
I HAVE SEEN IT IN SCHWINN ADS.
THE EARLY PHANTOMS DID NOT HAVE A DECAL 'BLACK PHANTOM' ON THE
CHAINGUARD. THE EARLY RED PHANTOM DID NOT HAVE THE 'PHANTOM'
DECAL EITHER.
AND THE PHANTOM STYLE REAR CARRIER TAIL/BREAK LIGHT WAS AVAILABLE
AS AN OPTION ON THE I948 B 607 AUTOCYCLE.
I HAVE SEEN AN EARLY AD FOR IT.