From an NFL standpoint, I can't help but feel like this is just another example of the Rams throwing money around, and it likely costing them later. Kupp is a solid WR, but its very clear he's not a #1, and hasn't shown any ability to win anywhere other than the slot. He's the perfect example of a guy a team should let walk after his rookie deal is up, because his skill set is easily replaceable.
From a fantasy standpoint, it solidifies Kupp's long term value, as there might not have been a better situation than the Rams are in the NFL for Kupp. Solid WR2 going forward, as long as McVay is around, and unless the Rams completely bottom out, McVay should be around for years to come.