There's no way around it. The seme's good at his job and the uke just entered there. Without knowing they'd meet, the uke must have already had this planned out.
Plus the fact that the their workplace forbids office romance. Sexual tension in the office be hard for them to avoid considering they'd just paired. And the stereotype that they have on omegas "sleeping their way to the top" and whatnot.
Of course it is the logical solution. But they could have discussed it, maybe delayed it for a month or two (while hiding their relationship). It's more about being mentally prepared and to have a plan for it.
First thing: I loved the story. It was beautiful.
But one thing bugged me immensely: They just established their relationship and without notice the uke just resigns from his work and goes independent? I mean there are huge risks involved and huge changes to your lifestyle. Could you please just discuss it with your partner so you can plan this out together?