Yes, and even more chance of that happening today than 5 years ago. Reason: because of the modern day prevalence of the ‘fake reply’ SPAM and Phishing emails. Spammers and phishers are now drafting fresh messages mocked up to look like replies in existing email threads…older spam detection used to let these types of messages slip through because they thought they must be legitimate replies, and so naturally spammers started exploiting that to slip past detection.