Would the capital gains tax change actually pass?

Predicting whether a specific piece of federal tax legislation passes is not something this site tracks or can responsibly forecast, since that depends on Congress and changes constantly during the legislative process. What is stable today is the existing home-sale capital gains exclusion under current law, which a CPA can apply to your specific numbers right now. Any future change would need to work its way through Congress before it affects an actual sale. Follow a source like the IRS directly for the most current, verified status.