It's not the same physical module. The physical aspects they list (megapixels, aperature) are the same, but the actual 48MP sensor they use is improved.

"iPhone 15 pro features a more advanced 48MP main camera, with an even larger sensor than iPhone 15 [and therefore iPhone 14 Pro]. The camera includes a new nanoscale coating to reduce lens flare."

See here: https://www.youtube.com/live/ZiP1l7jlIIA?si=FFSYTVqY0unVRSqu...

They also mention it enabling new focal lengths and better low light performance.