You’re talking about link aggregation (LACP) here, which requires specific settings on both the switch and client machine to enable, as well as multiple ports on the client machine (in your example, multiple 50Gbps ports). So while it’s likely possible to combine 50Gbps ports like you describe, that’s not what I was referring to.

No, I'm not talking about LACP, I'm talking about configuring four 50Gb links on the switch to operate as a single 200Gb link as if those links were wired up to a single QSFP connector instead of four individual SFP connectors.

The switch in question has eight 50Gb ports, and the switch silicon apparently supports configurations that use all of its lanes in groups of four to provide only 200Gb ports. So it might be possible with the right (non-standard) configuration on the switch to be able to use a four-way breakout cable to combine four of the 50Gb ports from the switch into a single 200Gb connection to a client device.