This is widely known. The consensus from reading on here is that this so Gifted Companions get a freebie, and that magi from a tradition with "favoured abilities" (like Hermetic Magi with their Arts, Vitkir with all their runes, Holy Societates and their sets of powers) get their special abilities at zero. I'm sure if you use your search-fu you will find a thread on this somewhere on this board as it's definitely come up before.
EDIT: such as https://forum.atlas-games.com/t/poll-gifted-companions/10399/1 (in Loch Ness PBP silveroak mentioned this), I'll look for more when the boards search function lets me.