Well, Boras is his agent so it's possible we see a redux of last offseason (and with Correa) where he holds out for the big contract and then is forced to sign a short term deal after no one caves on the outrageous demands. In that situation, the Brewers could work their way in, and it's not like the Brewers haven't agreed to a similar deal recently with Boras for Hoskins.
Could easily see Boras setting a value based more on the MVP caliber player Bregman was from 2018-2019 which no one is going to pay because Bregman isn't that player anymore.