To be fair, I'm pretty sure his logic is just that starting wage adjusted for inflation would be $31 an hour to put into perspective how amazing the starting pay was 40-50 years ago, not that it should be $31 an hour, because that would be pretty silly these days.
What I don't get is why it's not at least $15. People have been fighting for a $15 wage as the ideal minimum living wage for years now, and ups used to pay new hires WAY better than that. As it stands with this contract, new hires will basically get to look forward to barely making more than my city's current minimum wage. Right now, Portland's minimum is $12, and it'll be $14.75 in 2022, compared to ups's $13-$15.50. We have extreme trouble holding onto new hires right now because the minimum wage means they could go somewhere else and make basically the same money with a fraction of the work and stress, and I don't see this contract changing that.
At the very least new hires should get GWI as well (or rather, which ever is greater, the bump or GWI, since there's one year with a dollar raise instead of 50 cents).