I agree that states like Iowa/Ohio don't represent the future of the party, but we also need to be concerned with the present of the party. The point where North Carolina, Arizona and Georgia are reliably voting blue is still several cycles away. If we can still win some rust belt states in the meantime as a Plan B that's something worth pursuing, even if we count them as Tier 2 or 3 states.
If I were looking at the electoral math in 2020, here's how I'd prioritize the states (with all the knowledge that five months into 2017 has given me):
Tier 1 flips - Pennsylvania, Michigan, Wisconsin (even if these are trending red, they were extremely close and these three alone would have given us the presidency)
Tier 1 holds - Minnesota, New Hampshire, Nevada
Tier 2 flips - Florida, North Carolina, Arizona, Georgia
Tier 2 holds - Colorado, Virginia, New Mexico
Tier 3 - Iowa, Ohio, Texas