Smoke alarm and fire monitoring

Does SimpliSafe fire monitoring work with pre-existing, non-SimpliSafe smoke alarms - without a SS alarm? I assume not, since I couldn't find any mention of that anywhere, but I thought asking can't hurt. If the answer is "no", for my education, I would like to understand the technical reason, too - what communication piece is missing? As I understand it, "smart" smoke detectors do communicate wirelessly with each other, so in principle they should be able to communicate with other devices too.

Assuming fire monitoring requires a SimpliSafe smoke detector... can the SS detector be integrated with the existing ones? The wired ones are interconnected (when one is triggered, all will go off). I mean the question in both directions: when one of the existing alarms goes off, it will also trigger the SS alarm (and therefore alert the monitoring station); and when the SS alarm is triggered, in addition to alerting the monitoring station, it will also trigger all the other (pre-existing) alarms? I assume the answer is "yes"; if it is "no", does that mean I must replace all ten alarms throughout the house?

Thank you!