Spam is content that is delivered to people who did not request it. Slop is content which pretends to be what you want, but turns out to be of low quality.
Computer generated fake texts are spam, doesn't matter if they're selling pills to me or my attention to ad networks.
Slop = technically what you asked for, but intentionally created just to fill space and increase traffic/hits, generally of the lowest quality rendering it unusable
Would you still consider that "spam"?