The original Robin actor Burt Ward is ing the Batwoman, the Arrowverse has a lot of heroes at its disposal and have made stars out of Stephen Amell's Arrow, Grant Gustin's Flash, Melissa Benoist's Supergirl, and Caity Lotz' White Canary, just to name a few.
However, the Arrowverse also exists in a multiverse, as Supergirl and Batwoman are from different Earths than the one that Arrow, Flash, and most of the Legends originate from. These multiple universes have allowed them to have plenty of fun with crossovers and utilize past versions of heroes for their own gain. This year's Crisis on Infinite Earths event will put Brandon Routh back in the Superman suit too, and now we know of another familiar face who will appear in some form.
During the Batwoman at San Diego Comic-Con 2019 (via CBR), it was revealed that Burt Ward has a role in the crossover, where he will debut in the Ruby Rose-led series. Ward played Robin alongside Adam West's Batman in the original Batman TV show. He has continued to lend his voice to the role over the years, but now he'll make an appearance in the Arrowverse. But, it is not confirmed that he will play his original version of Robin, an alternate version of the character, or a new character altogether.
Ward's return to a live-action role in a DC story is exciting news for longtime fans of DC's history on the big and small screen. While many will surely hope that he is playing a grown-up version of the original Dick Grayson, it remains to be seen if that is the case. The Arrowverse has handled bringing past DC actors back in various ways before. Former Wonder Woman star put John Wesley Shipp back in his original Flash costume.
Even if he doesn't put on the Robin costume again, it would seem to be a missed opportunity for the Arrowverse to bring Ward into the fold and not have him be the same character. His inclusion in a crossover built around parallel universes (and the destruction of them) is hopefully an indicator that Ward will play Robin though. But, since that is not yet confirmed, we will have to wait and see who exactly Ward will play in the Arrowverse.
Source: CBR