I was wrong, I was just mistaking the process I remember following.

Instead of using the react-native command:

npx react-native build-android --mode=release

I used expo to generate the .aab build and expo generated a keystore for me.

I used the following command to check the sha1 of the first .aab file I generated:

keytool -printcert -jarfile app.aab

Downloaded the keystore using eas credentials command as suggested from @Mike and got the sha1 for that keystore file with the following command:

keytool -list -v -keystore release.jks

and finally found out the two sha match!