The only changes they made in the models was to change inflection points when shelter in place and other restrictions on activity were put into place.

Pretending that the experts were wildly wrong but now they’re right is either woefully ignorant or intentionally dense. It’s not like the experts who made the models didn’t come right out and say exactly that when they made the changes.

Here’s one of the earliest papers, with predictions ranging from tens of thousands to millions dying depending on actions taken to suppress the spread of the disease. As you can see, the high end of estimated deaths always occurs in cases where the government doesn’t do anything which is why the big graphs in the attached link all have “UNMITIGATED” underneath them.

https://www.imperial.ac.uk/media/imperial-college/medicine/sph/ide/gida-fellowships/Imperial-College-COVID19-NPI-modelling-16-03-2020.pdf