Update pages/stack/interop/superchain-upgrades.mdx

Co-authored-by: soyboy <85043086+sbvegan@users.noreply.github.com>

Author: krofax

pages/stack/interop/superchain-upgrades.mdx

@@ -46,7 +46,7 @@ Through this signaling:
 ## Activation rules
 
 **[Activation rules](https://specs.optimism.io/protocol/superchain-upgrades.html#activation-rules)** define the conditions under which a network upgrade or hardfork becomes active within the Superchain. 
-These rules can be based on specific block numbers or timestamps, dictating when the new protocol changes take effect. 
+These rules are based on specific timestamps, dictating when the new protocol changes take effect. 
 
 *   **Block Height Activation:** The upgrade activates at a predetermined block number.
 *   **Time-Based Activation:** The upgrade becomes effective at a specific timestamp.