Eu acho que não, como todos os estados de sessão na memória também são perdidos. De acordo com a documentação da Microsoft em Iniciar ou interromper o servidor Web (IIS 8) :
You can stop IIS when you want to stop the web server from serving content, such as when you upgrade applications. To stop the web server, you must stop the Windows Process Activation Service (WAS) and the World Wide Web Publishing Service (W3SVC). You can then start the web server when you are ready for the web server to serve content again.
When you stop WAS and W3SVC, all sessions connected to your web server are dropped. Any in-memory session state is lost. All sites are unavailable until these services are restarted. Therefore, avoid stopping and restarting your web server if you can.
Sobre Atividade de redefinição do IIS :
IISreset.exe is a command-line utility that can be used to stop, start, and restart IIS Internet services.
Note: Restarting or stopping IIS, or rebooting your Web server, is a severe action. When you use IISreset, your Web sites and applications become unavailable, all sessions connected to your Web server are dropped, and you lose existing state in your applications. Changes to the metabase can be lost. Your Web sites and applications will be unavailable until the affected Internet services are restarted.
The IISreset command stops and restarts the IIS Admin Service, the Windows Process Activation Service (WAS), and the World Wide Web Publishing Service (WWW Service).
Avoid using IISreset unless absolutely necessary. Instead, first try to restart an individual Web site or an individual application pool that may be causing problems.
Visão geral sobre o log do IIS :
... When a loggable event, usually an HTTP transaction, occurs, IIS calls the selected logging module, which then writes to one of the logs stored in %SystemRoot%\system32\Logfiles\.
Tanto quanto eu posso ver, em primeiro lugar, uma transcação de HTTP deve ser concluída para ser registrada e, em seguida, o serviço de log também deve ser executado até que termine de escrevê-lo. Portanto, há uma área cinzenta entre a parada e o início das solicitações em voo e pouquíssima chance de ser gravada totalmente para registrar. Também depende de quanto tempo os serviços relacionados aguardarão antes de desligar.