The largest effect is that X suddenly (out of nowhere?) started to mention this, publicly. Which, given mr. Musk's political stance (who himself has been the target of a campaign, likely from mr. Putin), wasn't intended to have this effect.

If you were to share this information publicly from the start, the troll/propagandist/agent would know this information is being shared as-is from the start, and they could adapt. Very likely they would adapt. Therefore, the effect would be much less severe.

It is also very obviously PII, which would hurt innocent people (likely a minority but I can imagine it happening).

My take: intelligence agencies were already interested in said information and mr. Musk was like "whatever, we'll just share this with everyone".