In the Truth Social post that the provided link references, Trump said that the elimination of income tax would focus on those making under $200,000. In another source, he has verbally said, "that the revenue raised by his tariffs 'will be enough to cut all of the income tax' in the U.S" (CBS).
Either way, income tax will not be entirely eliminated because the potential revenue earned from tariffs would not come close to the sum of income tax revenue. The current tariffs would raise $170 billion this year; in comparison, income taxes from earners under $200k would raise $700 billion this year. The math doesn't work.
It should also be noted that, while Trump has the power to execute tariffs, income taxes can only be reduced through Congress. Therefore, Trump does not have the individual power to promise that he will eliminate income taxes. According to Erica York, the vice president of federal tax policy at the Tax Foundation, Congress would not agree to this replacement due to its impossible viability.
Additionally, there are few current measures being taken to see a reduction or elimination of income taxes. There is only an attempt to extend tax cuts from 2017 through a reconciliation bill, which will also eliminate taxes on employee tips.
Even if income taxes were to be replaced with tariffs, there would be far more economic hardships than benefits for those making under $200,000 per year. This is because middle and low-income Americans spend more of their income on the basics taxed by tariffs than high-income Americans do. Where low-income households will likely see their disposable income fall by 5.5% due to the current tariffs, disposable income will only fall 1.9% for high-income families (Yale Budget Lab, cited in CBS).
https://www.cbsnews.com/news/trump-tariffs-tax-cut-below-200000-income-what-to-know/