Bit of a desperate article.

She was trained by the red room and that's the end of it. She's not been introduced to the mcu as a new black widow in the slightest.

On that note yelena hasn't even been introduced as a replacement...

You've missed out the police report for a crash dated 3 years ago.

Teen was killed in a car crash at the exact moment the hex ended, child billy m went into teen billy ks body. That's a proper theory.