I'm having trouble parsing your sentence... Are these examples? If so, they don't sound like poor or lazy writing, it's more stylized writing. They're not vague or ambiguous, they're actually very clear and concise (even if they use non-standard grammar)
You can totally say "Nah. I'm good", but I'm just really curious. What comes up in your mind if you imagine yourself reading one of those emails and being perfectly okay with it?