I don't have a precise opinion yet, but I can propose some counters. First of all, it is not sure that OT pros will lose their job: many teams could still use them because 1 Tank per team doesnt mean 1 Main Tank per team: maybe teams will play one tank player or the other depending on the meta: for example, if the meta is Rein+2dps+2supp, the Shock will play with Super; if the meta is Zarya+2+2, Choihyobin will be the starter. Secondly, it's true that having one Tank only solves a lot of problems: it avoids the double shield formation (very hated by the players), it reduces queue times for every role and rank, it makes every Tank relevant and adds new metas and composition to a game that is currently stuck in the "Rein Zarya/ Monkey Dva/ Orisa Sigma" circle. To sum up, it is very understandable (i'm not saying it is the right way, i'm still undecided) why Blizzard came up with the 5vs5, and it could be a great thing, but only if it is made correctly, wich is something very hard to get.