update ipod touch 7 without itunes update?

I believe that iOS 15 requires iTunes 12.12.0.6 as a minimum, so I think that answers your question. In addition, 12.12.0.6 has some sort of security update in it, so wisdom suggests that you should update to that version and preferably the latest version.

The most recent version (on the day of writing this) is iTunes 12.12.2.2

Here's a couple of things to think about:

• I've been using iTunes 12.12.2.2 since it became available (29th October 2021) without any new issues. Any problems I'm having with this version were there in 12.11 too, so although the niggles I've got have not been addressed, I am not personally aware of any new ones
• perhaps you should ask yourself (or those who tell you not to update) precisely why you shouldn't update. Do people who "advise" you not to update have a vested interest? Think about it, if a new release of a software programme has security updates in it designed to prevent malicious attacks on your information, it may be in the best interest of those who want to get at your information to advise you not to update iTunes. As I previously mentioned, the first release of iTunes 12.12 has a security update in it, so your version of iTunes does not fully protect you
• the last version of iTunes 12.11 (12.11.4.15) was released on 9th August and superseded by iTunes 12.12.0.6 just over a month later on 20th September - and it contained a security update! That should tell you something

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the fiend wrote:

The most recent version (on the day of writing this) is iTunes 12.12.2.2

Update: 8th March 2022, iTunes 12.12.3.5 released.