Whew, that's a whole can of worms . People have lots of strongly held opinions on this, varying from no treatments at all to pasteurizing to sulfiting to boiling. Pasteurizing must (as opposed to honey) is generally thought to be a reasonable compromise between bug control and not abusing the honey. Pasteurization is a function of temperature over time, so the lower the temp the longer to effectively pasteurize. I don't think 130 would be an effective temp even with extended time, but I'd have to look that up (been awhile).
I suspect one difference is that heating honey will inevitably cause some degree of caramelization due to its viscosity, and Maillard reactions will progress rapidly in so dense a medium, darkening the honey and changing the flavor. This will happen to some extent with must but not nearly as much.
It's largely a matter of opinion and experience re: pasteurizing (or other sanitization regimens). With clean equipment, well-treated honey and healthy, vigorous, well-pitched and aerated yeast of adequate cell counts, the yeast will outcompete many of the organisms that we worry about. Nonetheless, every honey has some degree of osmophilic wild yeasts in it. Wild yeasts are ubiquitous on Earth, and mazers need to decide how much treatment is enough to balance the effort of combating them with the risk to the mead with the risk of having them contribute (perhaps negatively) to the finished mead.
Personally, I pasteurize sometimes and also just control the variables to the best of my ability and pitch cold sometimes. I do propagate my yeast in media I specially prepare and sterile-pack myself, continuously aerate with filtered air, and have a biological nature so I baby my yeast pretty shamefully . I'm also a very effective sanitizer of equipment and environment if I do say so.
This is an area where in many mazer circles (Beesource, predictably, is more civil and respectful than many) where some opinions are so strongly held that some folks "wouldn't touch a sulfited/boiled/whatevered mead if you held a gun to my head" or whatever. The truth is wonderful meads are made in any number of ways; each has its benefits and detractions.
Bees, brews and fun
in Lyons, CO