They (almost certainly) mean linear regression, which many people appear to regard as statistics and boring, as opposed to single layer neural networks, which are cool.
To be fair, this is a pretty common perspective in computer science academia and adjacent fields (and probably occurs in a lot of fields where people don't focus on statistical learning..ahem I meant ML).
>...non-machine learning techniques, e.g., regression.
Is this where we are now? The connotation of "machine learning" doesn't include regression? Wow.