Microservices / modules – do you check references validity?

Consider examples like this: – user places an order with some items IDs. In the ordering context, we do not know if the ids are really connected to „our” products. Do you call the catalog (or whatever owns products) to check the products in order? – user creates an „event” (like a concert or conference etc) which takes place at PLACE and is organised by some organisation(s). Both places and organisations are owned by other contexts. Do you check if all references are correct?

Share your approaches and experience with them.