Emergency! Potterheads can you help me with the listening of this spell in the new trailer?

That’s not a spell. Someone (who sounds suspiciously like McGonagall) says “Mr. Scamander!”

The story is about a character called Newt Scamander.

To me it sounds like she is exasperated, repeating “just a smidge”, but there is some other sound in her voice that almost sounds like backward masking.

It’s definitely Mr. Scamander

Yep, she yells “Mr. Scamander”.

I’m pretty sure that it is either Queenie or Tina Goldstein who yells it