For years I was able to format a drive FAT32 (not my preferred formatting) and exchange with ease. THAT STILL WORKS.
Today I can format NTFS and current Apples have no trouble with that.
Who is telling you this story?
Are there external hard drives available that can be used interchangeably with pc and mac? We have a couple of externals that are compatible with both pc and mac but cannot use one between the two interchangeably because if the drive currently has pc data on it, when switch to mac it has to reformat and therefore would wipe all the pc stuff off. Currently we have a dedicated drive for each but would like to have one for pictures and movies that we can use interchangeably. I thought I saw something about one that does that in passing in the store one day but now cannot remember where it was I saw it.