Canvas will be updating the Deployment ID Naming for LTI Compliance. Deployment_id will be named lti_deployment_id after this change. Here's the link of this announcement for reference.
Please advise if this is a change that you will be implementing as well in the future. If yes, do you have any timeframe that you can share with us?
For posterity, that Canvas breaking change announcement reads:
"Updated Deployment ID Naming for LTI Compliance
To ensure compliance with the IMS LTI specification, the naming convention for the deployment ID in LTI login requests is changed to lti_deployment_id. Previously, the deployment ID was sent as deployment_id. "
Moodle was already compliant in its use of lti_deployment_id, so no changes are planned. See the code here: https://github.com/moodle/moodle/blob/e8ec0979dc01291c15392946e4ada4c225b1ab1f/mod/lti/locallib.php#L3671