Hi, here’s a link to the update notes Apple published when iOS 27.2 was publicly released.
About iOS 27 Updates - Apple Support
I suspect the major cause for the size is related to Siri.
“Siri AI (All iPhone 16 models and later, iPhone 15 Pro, iPhone 15 Pro Max)
- Siri AI can recall your past conversations, so you can ask Siri about something it told you before, like the restaurants it recommended last week
- Siri AI can draw from more sources to give you a great answer, including photos attached in Messages, Calendar event attendees, your voicemails, and better results from Safari history and Reading List
- Excluded Apps lets you choose which apps Siri, Search, and suggestions can access, all from one setting
- Granular text selection lets you select and copy just the part of a Siri response you need
- Siri AI is available in more languages, with support for French, Japanese, Korean, Portuguese, and Spanish. Siri AI is not available in the EU or mainland China”
