I have and I see very little evidence for it.
- The two reporters who broke this rumor are both represented by Trace Armstrong, the same guy who reps Kelly. That's not likely a coincidence;
- Kelly has zero NFL experience, even as an assistant. That makes him a tremendously risky hire for any pro team; and
- ND is a destination job. Thus, if you can succeed in South Bend, it's one of the few places where long-term job security is available. These rumors are about creating leverage so Kelly and his assistants get that security (which is notably absent in the NFL).
I suspect that Swarbrick is involved as well.
* Have you considered that the two reporters who broke the story are simply leveraging their connection with their agent, for their *own* professional gains, and are simply breaking a legitimate story? I would expect a reporter who shares an agent with the coach in question to be one of the first to "hear" about it.
* The NFL has been tapping into the FBS-well all off-season looking for the next Jim Harbaugh.
* Kelly doesn't seem to be too concerned with job security. He's a climber which you've acknowledged in a previous page. He's very ambitious, a risk taker, who has shown a penchant for putting himself and his own gains above his players, team, coaches, etc. The NFL in the modern landscape of football IS the next eventual step. The top NFL coaches make almost twice as much as the top FBS coaches.
It's perfectly plausible that this is just a very aggressive ploy for a bigger payday from Kelly, and he has every intention on staying at ND. But it isn't entirely out of the realm of possibility that the man is leveraging another successful college stint into an even bigger opportunity at the next level.
ND being a "destination" job (by your criteria) 20-50+ years ago doesn't tell us anything given the modern billion dollar industry the NFL has become.