Rogue One: A Star Wars Story features a motley crew of Rebels attempting to steal the Death Star plans, but some confusion was caused among Star Wars fans by the fact that there were no Bothans among them. Leading directly into Star Wars: A New Hope, Rogue One concerns itself mainly with the Rebels obtaining the plans for the Death Star, but it also serves to show in more detail the state of the Rebellion prior to Luke's introduction to it. The reevaluation therein focuses on the moral grey areas of the Galactic Civil War and the heroic actions of some decidedly unheroic people.
The Bothan race is absent from Rogue One, as it is from all Star Wars films. Appearing in more detail in the Legends canon, the Bothans were depicted as bipedal, lion-like species known for their skill in covert operations (although a modern-canon has yet to appear). Historically, their society has remained perpetually neutral in political matters, including the Clone Wars and the Galactic Civil War, but the Bothan Spynet was a premier intelligence agency and was often utilized by both sides.
A minor but commonly-voiced quibble that appeared following the release of Rogue One was that the central crew was exclusively human (apart from the droid K-2SO), despite a line in the original trilogy stating that "Many Bothans died to bring us this information." However, the line in question is actually spoken by Mon Mothma in Star Wars: Return of the Jedi and describes their efforts to steal the plans for the Death Star II, which was not yet even a glimmer in the Emperor's eye at the time of Rogue One. The effort to obtain the plans for the original battlestation are not given such detail in A New Hope, which was likely one of the reasons that the incident was more attractive for use in a standalone film.
Bothans have not yet been reintroduced to the new Disney Star Wars canon following the movement of most of the series' lore under the Legend legacy banner. But, as evinced by projects like Star Wars Rebels and Star Wars Jedi: Fallen Order, the time period between the prequel and original trilogies is one that Disney is particularly interested in exploring, and there is ample opportunity to feature more prominent Bothan characters in such stories, the use of espionage being especially prevalent among the major galactic powers of the time. Bothan society also has a history with the Galactic Republic stretching back thousands of years prior to the prequels and likely extending long after the sequels, so their use isn't limited to the Galactic Civil War.
There is no reason that Bothan characters couldn't have been included in Rogue One, and indeed their reputation as spies could have been put to good use alongside the film's themes of moral ambiguity and deceit. But it likely would have just exacerbated the confusion over Mon Mothma's line that arose even without their presence. Nevertheless, as Disney continues to put more focus on the fringes of Star Wars society with shows like The Mandalorian, Bothans could be a natural fit for future stories, perhaps even Cassian Andor's solo series, finally creating a true connection to Rogue One.