That has happened to me several times and with varying amounts of population.
The last time it happened to me was a few weeks back and it took me a while to get my country out of the mess it was left in. I added 5M population. I got the LLWs ok, loads of them, but did I get a single nurse, teacher, doctor, senior doctor or university teacher to cover the fall in indexes created by a population boost?
No such luck. I didn't get a single one, other than those created by the country's education system.
I have emailed the GM about it, but it has never got me anywhere.
The population will arrive eventually, but it takes a while, comes in bits and pieces and I'm still not convinced I received everything I should have. This makes planning unnecessarily difficult, particularly getting CEO investment. You should be able to just post in the forum that you have added population and then accept the forthcoming requests. However, the reality is that if your population isn't added as it should be, you will have to CONSTANTLY monitor the worker situation, make adjustments as and when required and add new corp requests one at a time, possibly over several weeks for say a boost of 5 million.
THIS IS NOT GOOD!
From my own experience, it happens in some countries occasionally, but not at all in others.
My LU main has suffered the most with this problem. I won't be adding any further population to that country, preferring instead to just let it grow naturally.
The GM can deny this happens all they like, but it does happen and it is a problem.
Regards
Kiteless