SERVER-95436 added the requires_timeseries tag to multi stmt txn concurrency suites because timeseries operations can't run within transactions. When the transaction override finds that it can't run an operation within a transaction, it retries the entire state function outside the transaction. As a result, each state function was being executed roughly twice - once within a transaction which fails, and then once more outside a transaction.

SERVER-95436 added the tag to exclude timeseries tests from running on multi stmt txn suites because these tests were effectively being run fully outside of transactions due to the timeseries incompatibility, so there was no benefit to running them on multi stmt txn suites.

Example that isn't tagged but is timeseries.