There are only two types of retirement savings, one is ROTH IRA where you pay the tax now, or 401K and Traditional IRA, when you pay your tax when you withdraw later. If now and later tax rate are the same, it makes no difference if you put your money in ROTH IRA or Traditional IRA.
However, if Tax rate now is > than tax rate later, it's advantagous to save using 401K or Tradiontal IRA.
If tax rate now is < than tax rate later, it's advantagous to save using ROTH IRA.
If you understand the above, here is the key infomration: Trump tax cut is effective from 2018-2025, after 2025 the tax rate is going back to pre-2018 level.
Assuming your income is same in 2018 and 2038, and you will withdraw from your IRA in 2038.
If you invest in Roth IRA, you pay your tax in 2018, let's say it's 22% now.
If you invest in Tradtional IRA or 401K, you don't pay your tax in 2018, but you pay tax in 2038 when you withdraw. Is it still 22%?
No, why? Because in 2018-2025 due to trump tax cut, the tax rate is lower. In 2038, the tax rate would be back to pre-2018 level, and your tax rate might be going back to 25%.