I am not advocating for Plawecki to have kept his job, being on a Major League roster is not a guarantee for anyone--as Joe Morgan said, "Baseball is only fun when you're good at it." And in a vacuum, dumping Plawecki so that the Red Sox can take a look at a minor leaguer makes all of the sense in the world.
Having said that, a Major League clubhouse does not exist in a vacuum, it's populated by real people who have real workplace relationships who show real emotions when their friend is unceremoniously axed with two weeks and change left of the season. Like others have said, the correct time to release Plawecki was three weeks ago and that's because he'd probably get a chance to catch on with another club. By releasing him now, he could catch on with a non-contender (doubtful) but even if lands on a contending team, he won't be eligible for the playoffs.
For a team stacked with veterans, that's a bad look from the front office. Based on quotes that have run here-and-there, I don't think that the players are particularly fond of Bloom and the way he does business. When you don't treat employees the right way, it does start to affect morale and how people do their business. You can say, "LOL Boo hoo, go dry your tears on your millions of dollars" but that's completely missing the point. Whether you're paid minimum wage or a Major League salary, a person wants to feel more than just a number. It's human nature. We've all had instances in our work life when a popular teammate was let go and maybe we've acted the way that Eovladi has. It's simple frustration and for it to boil over like that, I think it points to a larger issue.
Getting rid of Plawecki was not a mistake. Getting rid of Plawecki now probably was. It's not a huge mistake for Bloom, but as a person who's had this job for three years and has been in the front office of a Major League team for more than ten years, I have to wonder when these mistakes are going to end? If he doesn't understand that the veteran-heavy roster of the Red Sox (many of whom won a World Series pre-Bloom and were pretty successful) is different than the mostly-younger, mostly-happy-to-be-here Rays; I don't know when he is.