Interesting info.

I can verify that neither Lapua nor Norma loads the 9,3x66/.370 Sako Mag.
The only factory loads I've come across are Sako's and Federal's loads.

Smart of them to market it as the Sako Magnum - a much more selling name especially on a market where the metrics never really have succeeded.

This has been discussed on the forum before but I must repeat that I fail to see any purpose or benefit of the new caliber, at all.
As Ripp points out, it has less energy than the formidable 9,3x64 Brenneke - to which it is also in Europe rather difficult to find factory ammo. RWS does load it, as does Hirtenberger, I think.
According to Sako's advertising when the caliber was new, it had the same energy level and trajectory as the .375 H&H. Interestingly, in their brochure they also published the trajectory curves where one could see the flatter trajectory of the .375...
How they achieved a flatter trajectory in some loads was simply through using a lighter bullet. Whoopee.

In saying that I see no purpose, I do of course see the caliber's potential especially on elk, bear, and wild boar. But with the 9,3x62 already existing, tried, popular and excellent by all means and not wanting in power plus the x64 being on the market as such for the recoil enthusiasts I simply don't see a place for it.
Boddington makes an interesting comparison considering the 9,3x64 Brenneke perhaps the only more suitable all-round safari caliber than the .375 H&H.
Additionally, given that in many African countries the .375 H&H is the minimum, Sako would have done better in introducing something in that category, maybe.
I suspect they may have been caught off guard by Art Alpin claiming the label for the .338-06. Given that Sako & Federal commercialized the .338 Federal they would have had a good chance in repeating it with the -06. That way Sako would have got its name on a caliber which they much wanted to do. There hasn't been a Sako caliber since the 7x33 I believe.