This is because only the following levels are allowed/understood in Sentry (https://docs.sentry.io/clients/node/usage/#raven-node-additional-data):
Sentry is aware of the following levels:
- debug (the least serious)
- fatal (the most serious)
We should send levels that Sentry understands, and map the levels we currently send as-is extracted from Java.
As we only send >= WARNING anyway, we mainly (only?) have to map severe to fatal.