Yes, it's true. Rather than recalibrate the MAF for the 24s, SVT re-used the 19# sensor and made the conversion in the computer. Cobras don't use the A9L, they use the X3C, which amongst other things, allows the use of the 24# injectors with a 19# MAF.
There is a little confusion here so I just want to clear things up.
The X3Z (93 Cobra) computer used a 70mm MAF with a XX MAS (I can't remember the part number for the Cobra MAS right now, but it is different than the MAS used on the A9* cars).
You will not have good results running a 93 Cobra MAF/MAS on a A9L Mustang, regardless of what injectors are used.
However, the 94-95 Mustang used a 70mm MAF with a F2VF MAS. This MAF/MAS can be swapped directly with the stock MAF/MAS on an A9* Mustang, IF stock 19Lb injectors are used.
Or, one could run a 70mm MAF tube from a 93 Cobra, with a F2VF MAS from a 94-95 MAS.
The MAS on the 93 Cobra is not the same as the one used on the A9* Fox Mustangs.
The X3Z (93 Cobra) computer used a 70mm MAF with a XX MAS (I can't remember the part number for the Cobra MAS right now, but it is different than the MAS used on the A9* cars).