Are you sure you're not mixing up ICP and AO (arweave's "super computer")?

As far as I understand, this is renting the nodes out to run code. The nodes are different then the gateways.
https://ao.arweave.dev/

This should not change the speed of gateways, and if it did from extra traffic, then more gateways would come on with all the extra revenue the service is doing to the coin(s) value(s).

Arweave uses modified BitTorrent as part of it's "Proof of Access" system to share among nodes.  But the gateways serve it to the end-consumer using regular https in a regular web browser.