>However they are not party to some decision loops and are often on the receiving end of architecture and design decisions. Most of them start to complain about that sooner or later, so I ask them to start participating in more meetings...

And if they decided to attend these meetings are they still expected to maintain the same "velocity/story points/etc."? Because if so then they will likely have to work outside of "office hours" to actually get the work done. Possibly why they decline and stop complaining... They realize they'll just get handed a bigger bag of BS.