What you are describing sounds performative, which doesn't mean it's tokenism, window dressing, or a bad faith put-on show. It could all be with the best intentions. However it's hard to disagree with your take that DEI results should be self-evident. If a company feels a need to be self-congratulatory, they might be doing it wrong.

You put your finger on it right here: "I could understand publishing a quarterly report, but creating townhall meetings and parading..." Women and minorities in tech have their networks and know what's what. Accurate reporting of positive results is what makes a company welcoming to applicants.