I could actually see the opposite, a coach saying they want a chance to work with marner.
It's interesting because I think the majority of coaches and GMs in this league would agree with this. Last year LeBrun talked to a bunch of anonymous GMs and the majority believed that the team is close, you do stay the course, and you try to change on the peripheral. We have over 18 million in cap space this year, 11 million more coming off the books from Tavares next year (51 million total at this moment), that's actually not that much of a cap crunch and grants a lot of flexibility.
It's very easy to see coaches and/or executives looking at this and saying "well, we use that 18.5 wisely this year, maybe catch lightning in a bottle because this is a good team, and then we have a ton of flexibility next year even after locking up Marner, I like the look of that."