You Won't Find Some Elite Athletes at the Games
In reality, the vast majority of MLB players will not be in Tokyo. While its "second-tier" players could be available, MLB's elite players will not. And from Barcelona 1992 through Beijing 2008, the last Olympic stretch for baseball before its Tokyo return, they did not, either. Simply put, MLB's team owners and players' union don't like the idea of shutting down the league's summer season for two weeks to accommodate the Games. (Meanwhile, the Nippon Professional Baseball and the Korea Baseball Organization have committed to the Olympic break.)
Outspoken MLB star Bryce Harper puts it frankly, "You want to grow the game as much as possible and you're not going to let us play in the Olympics because you don't want to (lose) out on money for a two-week period? OK, that's dumb". (Um... yes, baseball team owners are more interested to grow their immediate revenue than to "grow the game".)
Baseball may not get the chance again. The sport was not included in the program for Paris 2024, taking women's softball (despite embracing the Olympics) down with it. Very likely, the fact that the sport's biggest power brokers don't have an interest is a key to why baseball isn't a core sport for the Olympics. A return for Los Angeles 2028 is possible, helped by a United States-based Games, but MLB availability may very well again be an issue.
The vast majority of sports do see the Olympics as a unique, elite goal for its players. But MLB is not alone in some recalcitrance. Here is a look at how some other high-revenue professional sports approach the Games.
Ice Hockey
As the only traditional team sport in the Winter Olympics* since Chamonix 1924, ice hockey has a special position of interest from the International Olympic Committee in ensuring elite players participate. Aside from that background, men's ice hockey's relationship with the Games is similar to baseball's.
The sport's top professional league, the National Hockey League, has a team ownership structure reluctant to stop a season's play and risk revenue and player injury. And, similar to MLB's World Baseball Classic, the NHL has its own contrived international tournament, the World Cup of Hockey.
And also similar, other top leagues make the Olympics a priority. But every four years, there is another round of negotiations, with the NHL's business interests pitched against the IOC's and the International Hockey Federation's interest in presenting a top quality tournament to expand the game. NHL players appeared for the first time in Nagano 1998, and did so through Sochi 2014, but skipped Pyeongchang 2018. Current expectation is that the NHL will return for Beijing 2022. That's due in large part to the players themselves wanting to go.