If a company can't recruit an immigrant worker on a visa they'll try recruit one of the currently unemployed local developers on the exact same package the immigrant would have been on. That has no impact on wages.
If the job required a unique talent that would only have been possible to fill with an exceptionally talented immigrant worker then the job won't be filled, and the company will be consequently less competitive. That will likely drive the wages of their workers down if a different company (in India perhaps) is able to utilize that worker's skills.
For example, imagine the next Jony Ive can't get a visa so he stays in the UK and works for a British company instead.. How would that impact American wages?