The flaw with your arguments is that the pot of money is only so large. In the negotiated contract, IBT was likely more successful in securing larger increases economics than UPS had been willing to pay. You can already see the fallout, with disgruntled Freight and managerial employees. In other words, if you want to maintain the status quo benefits, you're going to have to relinquish a portion of your raise or contribute toward the cost (premium).
As I've previously written, consider the current benefits. The ER co-pay is so low that members go there for petty reasoning; they don't know and don't care that the ER is a VERY expensive place to visit. It's not free or low cost -- UPS is simply picking up the tab. There are oodles of other examples I can think of, such as members foolhardily filling prescriptions they don't want or need just because it's "free" and yields them at $25 gift card at Target, Safeway, CVS, etc. Higher costs & escalators in the new insurance are necessarily a bad thing. I would rather see a bigger raise than continue to pay for people's ignorant decision to take their kids to the ER because they got gas after eating a Bloomin' Onion at Outback.
Personally, I'd love to see a more modern health plan. E.g. One that charged $30-$40 (instead of $10) for a PCP visit, but waived two per family member per year as well as all those related to a serious illness (e.g. cancer). $500 per member would be deposited into a health savings account to spend on higher costs, as well as OTC drugs, etc. Such plans require more critical thinking on the member's end, and lower costs on the provider's.