Klaviyo Spring 2026: RCS Messaging, AI Audience Optimization, and Instagram Auto-Replies
A month in, in-app migration to the new features is rolling out more smoothly than expected, but RCS carrier coverage in North America is still climbing — older Android devices and downgraded iOS versions will fall back to plain SMS. Design RCS flows so they degrade gracefully: lead with the offer in text, then layer cards and buttons on top. If you're turning on AI Audience Optimization, hold out a manual control group for at least four weeks before switching fully, otherwise you can't separate algorithm lift from seasonality.