can't speak for Intuit but the 'why' is too many changes for the big bill and their focus is a working product for filing based on form specifications from IRS, rather than estimation tool. expect many updates the coming weeks/months. see this thread for advice - most features say Jan/Feb dates. You may be able to use forms mode for areas where the interview screens are not ready.
https://ttlc.intuit.com/community/taxes/discussion/turbotax-deluxe-2025-forms-availability/00/371366...
for estimation purposes you may just want to use other online calculators, try
https://www.dinkytown.net/java/1040-tax-calculator.html
