I mean, I think you're both right if they don't plan to spend up to a certain level. It really depends what other teams do, but if they only plan to use half of the money freed up this off-season, the team won't be good enough, and they won't necessarily be planning to add big salaries at the deadline either. If the choice is JT and JT only or 3-4 players instead of JT, neither is sufficient, but sure, the latter is probably better. The other problem is if they wait for JT's market to develop they will miss other options.
This stuff also doesn't happen in a vacuum. The Braves and Marlins aren't likely to get worse, the Mets may or may not get better (it's the Mets and spending money, as we now know ourselves, isn't always the answer), the Nats will probably bounce back (and have $ too). We're an 81-85 win team without much effort and if you don't make the playoffs who cares if you're in 3rd place or 5th place, but the latter is possible, and if that's how it goes, the rebuild will be looking pretty likely.
I think we have to be seriously worried that they won't even QO Didi. Unless they are so sure that they aren't signing JT anyway that his salary wouldn't be a problem. I'm also not sure he'd take it. There are actually more free agents in the next class. Whatever long-term security he can get now is probably better for him than being one year older in a more crowded FA market heading into a work stoppage.
But the owners also have a lot of leverage. Not only the austerity they obviously plan to institute, but most of these players are hurting too. I mean, boo-hoo, but Didi didn't make $14 million this year, he made $6 million. Whether that makes him more likely to just take the guaranteed $18.9 or more willing to take a lower AAV long-term deal, who knows?