The recommended value (sizing) for BGP prefixes had been changed.
BGP Prefixes (Recommended): 150 (old) => 1,500 (new)
[Document]
BGP - Cisco Meraki
https://documentation.meraki.com/MX/Networks_and_Routing/BGP
> Platform Sizing Considerations
> For Z3/c platforms we recommend only advertising a handful of aggregates or a default route to the datacenter. For the rest of the MX Security & SD-WAN appliances we recommend sizing the BGP topology to 1500 prefixes from the DC. This is due to the fact that smaller appliances may also be running other features such as Advanced Security and Meraki Insight etc.
[Older article from the Internet Archive]
https://web.archive.org/web/20210423053730/https://documentation.meraki.com/MX/Networks_and_Routing/...
> For the rest of the MX Security & SD-WAN appliances we recommend sizing the BGP topology to 150 prefixes from the DC.
I contacted support to find out how it happened.
Previously, 150 prefixes was the recommended value.
However, according to support, the value was very small and was reviewed.
Incidentally, I have not heard the basis on which it was multiplied by 10.