Unlike a 529 plan, the tax benefit of using I-Bonds for tuition is only available if your AGI is under a certain amount in the year you cash them in (currently $154k for a married couple). https://www.investopedia.com/ask/answers/111414/what-educati...
The same AGI phase-out applies in the year that you do the rollover.
So this doesn’t allow you to avoid the income phase-out, it just lets you time-shift the educational spending to an earlier year (in which your income may be below the threshold).
If your family income is above the threshold in every year until you need the money for tuition, then there will not be an opportunity to get the tax benefit.
From your link, emphasis mine:
> Taxpayers can bypass the income phase-outs on savings bonds by rolling them over into a 529 college savings plan before their income increases beyond the income phase-outs.