Do single ticks get converted into double ticks if the person I sent a text reinstalls WhatsApp after uninstalling it?

Hey, here is something I've observed and need some validation on:

 Friend A sent whatsapp message to friend B AFTER B uninstalled WhatsApp. Friend A sees only single ticks - understandable. Friend B reinstalls WhatsApp after 7 days - it is my understanding that they will get the message friend A sent (as long as they reinstall within 30 days). Does friend A however see a single tick only at this point of time or a double tick?

What if the 7 days duration is reduced to 1 or 2 days? Do the single ticks ever get changed to a double tick? I have been friend A and the single ticks remained single always (I don't know if B got message I sent after B reinstalled the app after 7 days). Now I'm friend B and I'm wondering if friend A has a single tick as well and since I reinstalled the app a day later, I got the message A sent AFTER I uninstalled the app but is their single tick going to be a double now?

Well what I understand in Whatsapp is -

WhatsApp ticks aren't very reliable, IMHO. Ideally, 'A' should see double-ticks; if they've received the message. WhatsApp stores messages on the servers and delivers them only when the recipient is available. 

I doubt they track whether the receiver has the app installed or not. Only possibility could be that they've disabled read-receipts.