All of the catalog data was moved to a service which only served catalog data so its cache was optimized for catalog data and the load balancers in front of it could optimize across that cache with consistent hashing.
This was different from the front end web tier which used consistent hashing to pin customers to individual webservers.
For stuff like order history or customer data, those services sat in front of their respective databases and provided consistent hashing along with availability (providing a consistent write-through cache in front of the SQL databases used at the time).
I wouldn't call those areas where it makes things more efficient rare, but actually common, and it comes from letting your data dictate your microservices rather than letting your organiation dictate your microservices (although if teams own data, then they should line up).