AFAIR: the BE200/B202 only have one radio. So no parallel streams on two frequencies.

But they are the best cards around if you want to play with Wifi-7 on Linux. But always go for the latest wireless-next kernel + firmware blobs. Also they are not compatible with AMD mainboards (go for Qualcomm then).

Being connected to multiple frequencies simultaneously is one thing. Actually using multiple of the links in parallel to increase speeds has not really been seen in practice yet. That is called STR (Simultaneous Transmit/Receive; what I called "throughput aggregation" above), which requires MLMR (Multi-Link Multi-Radio), which almost nothing that supports MLO has right now. Maybe some bleeding-edge mesh networks are doing it, and Ubiquiti has one or two products that does it, but you basically won't see it anywhere else and especially not in client devices yet. Intel BE200/BE202 does not actually perform throughput aggregation, it connects to multiple frequencies and then uses only the best of them (eMLSR, or "Enhanced Multi-Link Single Radio").