Can I still get Windows 10 free update even though I did not reserved? Because I still don't know why the Windows 10 free update icon in my taskbar doesn't show up.
The reservation is simply a data harvesting tool for Microsoft, plus it will download the upgrade for you in background prior to launch date. Just something to make people aware that a free upgrade is available. You already know about it.
There's no need for it apart from that, after launch you can download the ISO and install from that, or from Windows Update.