Take your pick:
https://twitter.com/JeremyECrawford/status/994993596989300736
"Clarification about bonus actions: if a feature says you can do X as a bonus action if you do Y, you must do Y before you can do X. For Shield Master, that means the bonus action must come after the Attack action. You decide when it happens afterward that turn."
https://twitter.com/JeremyECrawford/status/995016512497840134
"Curious why I changed my ruling on bonus actions? When there's a gray area in the rules, I lean on general rules or exceptions to determine a ruling. My original ruling relied on the general rule, but over time, the weight of the exceptions swayed me to a more logical ruling"
https://twitter.com/JeremyECrawford/status/995064126866010113
"In 2017, I clarified in the Sage Advice Compendium how timing works for a bonus action. The query there is about the Eldritch Knight’s War Magic feature, but as I've stated today, the answer applies universally to bonus actions with triggers. See
https://media.wizards.com/2017/dnd/downloads/SA-Compendium.pdf ..."
https://twitter.com/JeremyECrawford/status/995064841214676994
"Today's clarification makes it so that you can trust your book more than ever before, since I've now eliminated an illogical ruling that actually seeded doubt about the book's text."
https://twitter.com/JeremyECrawford/status/995069135905161216
"In 2017, I changed the ruling on bonus action timing because the old ruling was illogical. The original ruling failed to account for the fact that X relying on Y is a form of timing. The new ruling corrects that oversight."
He originally used the word "intent" in his ruling. He then realized he was wrong, and corrected that ruling. He's even used the word "intent" in describing the corrected ruling as of this week. Thus, I don't think you can say "well his 2015 tweet is still the correct one because that's the only time he described RAI".
If you don't believe me, here he is describing what the feature is supposed to be, i.e. the intent of the feature:
https://twitter.com/JeremyECrawford/status/994997405492772864
"It's supposed to be what it is: a way to knock someone prone after your attack. It's essentially a finishing move."