the article that you provided
https://www.google.com/amp/s/amp.usatoday.com/amp/3418926001
does not saying anything about 401K.
Biden’s plan raises taxes for high-income INDIVIDUALS, corporations.
According to https://taxfoundation.org/joe-biden-tax-plan-2020/
Details of Biden’s Tax Plan
Payroll tax and individual income changes:
Imposes a 12.4 percent Old-Age, Survivors, and Disability Insurance (Social Security) payroll tax on income earned above $400,000, evenly split between employers and employees. This would create a “donut hole” in the current Social Security payroll tax, where wages between $137,700, the current wage cap, and $400,000 are not taxed.[1]
Reverts the top individual income tax rate for taxable incomes above $400,000 from 37 percent under current law to the pre-Tax Cuts and Jobs Act level of 39.6 percent. (37% TO 39.6%)
Taxes long-term capital gains and qualified dividends at the ordinary income tax rate of 39.6 percent on income above $1 million and eliminates step-up in basis for capital gains taxation.[2]
Caps the tax benefit of itemized deductions to 28 percent of value, which means that taxpayers in the brackets with tax rates HIGHER than 28 PERCENT will face LIMITED ITEMIZED DEDUCTIONS.
Restores the Pease limitation on itemized deductions for taxable incomes ABOVE $400,000.
Phases out the qualified business income deduction (Section 199A) for filers with taxable income above $400,000.
Expands the Earned Income Tax Credit (EITC) for childless workers aged 65+; provides renewable-energy-related tax credits to individuals.