A free service that ties up a service bay but makes them no money...
This is where dealerships are failing. I realize I may be preaching to the choir here, but:
First - people don't want to buy bikes that don't have good support. Solid support is a huge sales boost. Crappy support is a big sales turnoff.
Second - when a dealership is a pain in the ___, people find ways to get around them. As an example, the folks who own our local BMW and Triumph shops have all kinds of super annoying things they do so I go out of my way to not buy stuff from them unless it is warranty type work. Like parts and accessories, I can get parts for less from Bob's BMW or Hermy's Triumph - even including shipping. If Bob's and Hermy's can sell me those parts, and not charge me all the bogus fees and stuff and it still comes in lower cost - then the local guys could do it too. They are penny-wise and pound foolish. For service? I either do it myself if it is simple or I do it at a place that is not the dealer (maybe an independent shop) because the dealer has priced themselves out of the thing. They charge like $100 to reset our service indicator - but hey, you can buy a GS911 and do it yourself. And on and on and on. They have lost more money from me because of their greed than anything else.
Third - letting people come in to get a software update can be a loss-leader. I have actually bought a new car while getting a car worked on before. I was waiting on the shop to finish and walking around the dealership, and decided to get a new one. I bought my R18 because I went in to kill some time and heard about their deal. I have bought all kinds of stuff like accessories and clothes and junk, just because I was in a place. If you give people a reason to be at your shop - there is a good chance they will spend money.
So with those three things, I think it would behoove a dealership to be eager to update people's software for "free". Heck, even require people to be members of a frequent buyer club or something like that. Lots of ways they could monetize it without charging for it.
But ultimately - word of mouth is also powerful, and companies spend a lot on advertising - which they can get for free just by being cool.