As if tipping had logical regularity to begin with? You're expected to tip at coffee shops long before receiving the service, and for takeout orders, where there is no service. (At least, they try to dupe you into thinking it's expected.)

"Add a tip to this order when placing it" sounds stupid, but it's only revealing the pre-existing stupidity of the convention it's trying to parallel.

If they go the other route like Uber and say "tip's included", then they trigger an angels-on-a-pin lawsuit about "well which part was the tip because you can't take a cut of that".