That's an M1 iMac and includes two Thunderbolt / USB 4 ports and two USB 3. If it has 7 GPU cores then it includes just two Thunderbolt / USB 4 ports.
The ports are all USB Type C and are backwards compatible with USB A with the proper adapter or hub.
The hub you show should work with the iMac. The seller is just warning you that it may emit EMI that could interfere with Wi-fi. If it does then just move it to a new spot until it no longer interferes. The further from the iMac the better.