Trump is interested in votes and money. Bitcoin can bring both because it's not hard to be pro-crypto following pretty harsh measures of the Biden administration, and since Bitcoin is money, you can (and that's what he's doing) fundraise more for your presidential campaign from Bitcoin enthusiasts.
I don't support Trump as a politician, his views are far from my own. But, more importantly, I truly don't believe that Trump is sincere with his pro-Bitcoin stance, considering that he was consistently anti-Bitcoin for all those years before, and it's a very convenient time to change your policy.
I wouldn't doubt that Donald trump's sudden massive interest in Bitcoin is because of what he stands to gain if he aligns with it. Money and votes are the two things that can get him the presidency and being a pro Bitcoin is one big way to achieve this aim, most young voters are Bitcoin compliant and his supporters can donate to his campaign with Bitcoin. I think that it's a smart move for him to speak at the Bitcoin conference, whether he promotes Bitcoin or not if he becomes president doesn't stop the massive adoption of the digital cash. Bitcoin has come this far without Trump and Biden, giving it deserved recognitions, so no notable individual can stop what Bitcoin stands for.