Yeah, I don't really see the logic in that post. You will most likely see a slight rise in salaries across the board. In addition a larger effort to recruit for junior positions from universities and job listings.

The only real change is that recruiters will have to change there talent pools. There reliance on H1B is mostly because no one stopped them not because there is a lack of us talent.

Most of the consulting companies like Infosys, CTS etc work as such: They hire tons of people fresh out of college. Some of those have contractual obligations called "bonds" which force them to stay with company for 2 years or so. That is the stick. Later comes the carrot in form of H1 sponsorship a year or two down the line. So the median work ex for H1 tends to be 3-4 years. Then there are those who change jobs simply to get the promise of being sponsored. I know couple of people, one with Amazon, with over 8 years of work-ex joining as software analyst because it helps companies pay them least of salaries. If senior dev is the new norm they will shape the supply accordingly and try to suppress salaries in that direction. The only way out was(is?) to provide salary directions too but vague wording allowing companies to include non monetary benefits will again be suspectible to manipulation. But not doing so means startups will not be able to afford engineers with only monetary benefits. It is a very difficult problem to get around.

More supply of senior engineers will decrease salaries. The visas used to be taken primarily by junior devs preventing (some) senior devs from getting one. Senior devs may no longer be blocked which increases supply. Demand is unchanged, at least in the short-term.

In my experience of hiring engineers across several companies over the past decade, the pool of senior SDEs who are both not already in the US and willing to move to the US is so small that I'd be surprised if it even registered in the overall H1B flow. Virtually all the non-resident senior SDEs I saw getting hired in my orgs ended up being H1B transfers who got hired straight out of college into the US and grew into seniority while here.

The economics aren't so black & white. The incentives to hire an H1B change when companies are paying senior engineer wages for the position.

I doubt it. The number H1Bs for people with the equivalent of a Masters degree or Phd is something like one percent of all H1B visas.

I seriously doubt that a shortage of H1B visas would be an issue for a company that decides to hire someone into a senior position. Senior positions are handled with more care then junior positions.