If botanists say that something isn't wheat, then its use should be examined.
If botanists say it's wheat, it's probably OK.
Not RC, but given that the whole thing is a re-creation of a Passover meal (although certainly with all that comes with the New Covenent/Communion), I would think any bread without yeast would be perfectly acceptable to God.
Matzos being the easiest choice . . . but I am a practical guy.