Ok, I'm a little confused by what I'm seeing here. Windows Reliability Monitor is not in Win7, that I know of (perhaps I'm wrong on this account, perhaps MS added it), but MS Security Essentials is for Win7, and not for Win10.
What OS are you running here, is it Win7 or Win10? I'm confused, how MSSE is running on Win10, or Reliability Monitor is in Win7. I don't see how to get both on one OS.
According to this, "View Reliability History" has been in since Vista. Learn something new every day. I thought that it was a Win8.1/Win10 new feature. I apologize for my prior ignorance in that matter.
Computer dictionary definition of what the Windows reliability monitor means, including related links, information, and terms.
www.computerhope.com
---
Anyways, I think that "Anti-malware definition updates", can come via explicit Windows Updates, or through a back-channel using BITS service. That may be what you're seeing here?
Sometimes, Win7 updates MSSE, and behaviors change too. Was there an update to the MSSE executable files in the last few days.
I agree, that change might be a bit disconcerting, but MSSE seems to indicate that it's still being updated.
---
In short, I really don't know. But I do have some experience, through a friend, that sometimes the Anti-malware definitions updates, prompted the user to do a Windows Update. Every day. And some times, they didn't.