Will the ScamShield Bot be able to read my other WhatsApp messages?

No, the Bot will not be able to read your other WhatsApp messages.
A Singapore Government Agency Website
No, the Bot will not be able to read your other WhatsApp messages.
ScamShield does not filter calls or messages coming from a contact saved on your phone. To do so, we require access to your contacts. We do not store your contact list on our database.
Likewise, ScamShield requires access to make and manage phone calls, and access to send and view messages to be able to spot and filter scam calls and messages from unknown contacts.
We only store information on calls and messages from unknown contacts and which have been identified as scam to train our system, and better protect the community.
When you submit a report to the ScamShield Bot, the SPF will be able to see only the information you have submitted through the ScamShield Bot and the time stamp at which the report was submitted. For example, here is what the SPF can see:
For Message Reports: A copy of the submitted message, the reported sender information, and the channel submitted for the report.
For Call Reports: The caller’s number or ID, info submitted about the call, where the call was received.