No, no, no. Do not do this. It is bad advice!

First, asking for ANY precommitment not to break up over X is going to be a "major relationship step" and unless you are very experienced with relationships it is not something you ask for during the first two weeks, because there's a decent chance it'll harm or end the relationship.

Second, it's a stupid precommitment to agree to! There's all SORTS of good reasons to break up with someone who texts you, since the content can be basically anything.

Third, any breakup can be blamed on texts / emails, so it's a big red flag that you're going to be a serious creep if you ever do break up with them.

Phrased more specifically, in a stable, long-term relationship, and done by someone who is fairly experienced negotiating boundaries, this CAN be useful, but none of those qualifiers seem to apply here!