For clarity's sake though, we're talking about yield theft on what was IBM's already evasive 401k match. One's "real" 401k contributions remain separate, portable and their yield bounded only by IBM's limited choices/fees.
They used to wait until end of year to match funds until recently they switched to monthly matching. So if you left before end of year, your match didn’t pay out iirc. Now they’re getting rid of 401k matching entirely so suppose it’s a moot point.