Update avalanche-l1s.mdx

Signed-off-by: Martin Eckardt <m.eckardt@outlook.com>

content/docs/learn/avalanche-l1s.mdx

@@ -14,7 +14,7 @@ Avalanche's [Primary Network](/learn/primary-network) is a special Avalanche L1
 ![image](/images/subnet1.png)
 
 <Callout title="Note">
-Every validator in an Avalanche L1 **must** also validate the P-Chain of the Primary Network.
+Every validator of an Avalanche L1 **must** sync the P-Chain of the Primary Network for interoperability.
 </Callout>
 
 Node operators that validate an Avalanche L1 with multiple chains do not need to run multiple machines for validation. For example, the Primary Network is an Avalanche L1 with three coexisting chains, all of which can be validated by a single node, or a single machine.