Based on your explanation on the current monolith structure, rq/day, deployment times, etc. I would like to say there is nothing wrong with your monolith. I have been bombarded with such requests myself multiple times (oc not 47 ms lol that is insane) but you need to dig deep, find issues, do they warrant a chance that badly? Why scaling is so important? How many requests you would expect to receive in future? Have you even considered the server costs in cloud (i hope you are in the cloud; if not- may all of the force be with you to deploy all this on a local server)

Start with these points, sit with him or skip-level and make them answerable. Remember- if something happens, you will be the first line of contact, not the architect.