I think it's worth noting that this attitude towards '27/'28 would make just as much sense without the CBA expiring. You touch on why in your second to last paragraph. The team has practically no money tied up post 2026. Based on roster resource, it looks like this:
- Swanson's $28M is rock solid guaranteed
- Shota's $15M will probably get picked up
- Steele in Arb 4, let's call it $10M
- Assad at Arb 2, I'd be shocked if that's much north of $5M
- Amaya, Busch, PCA, Hodge, and Palencia at arb 1. Barring some incredible developments none of those guys except PCA will top $5M. PCA might approach 8 figures
So the team's got ~$100M in LT payroll committed in a year where the LT line is going to be at least $245M, and 1/3rd of that isn't even guaranteed. Even conservatively that's $100M available to sign players for the FO. Contrast that to this winter, where there's ~$50M available by the same assumptions, and a Tucker pursuit would take up most of the available cash on its own.
An Edward Cabrera making ~$5M next year and projected for ~3 WAR is hugely valuable given the likely financial limitations. In 2027 though, there's not that same financial calculus because the marginal value of a dollar saved is pretty low. Ditto 2028. He's not worthless after next year, but if you did some $/WAR calculus I'd bet 80+% of the utility in a trade would have projected to come these first 15 months. Gore and Ryan, under control one fewer year, it'd have been more stark.
I also kind of wonder if the prospect timelines influence this too. '27 is probably when you'd start to prefer having e.g. Wiggins and Caissie than Cabrera. So from the Cubs' POV I could see an argument that "you have to make things really worth it for us up front because we're going to lose the back half of the deal", almost like a FA contract.