sure
As long as you can find the installation package 14 can be installed, there is no mandatory requirement. If you upgrade from Apple's official website, it depends on whether the download channel is closed, if it is not closed, you can upgrade.
After upgrading the iPhone12 to the official version of iOS15.4, it obviously feels more smooth than the official version of iOS15.3.1, the sensitivity of the touch screen has been improved a lot, and the touch and slide are more closely followed. We have tested a number of commonly used apps, such as wechat, QQ, Toutiao, Weibo, etc. Personal feeling is that the official version of iOS15.3.1 opened faster, basically click the APP can enter the second. The up and down slide in the APP is very smooth, without a bit of stuttering.
At present, the iOS12 system cannot be upgraded directly to 14. Apple's latest version of the system has been updated to iOS15, so you can only upgrade directly to iOS15 version. The upgrade channel of iOS14 has also been completely closed, and there is no way to upgrade to iOS14 even through other means. Personal recommendation can keep ios12 system, this system is relatively stable.
Of course you can. As long as you can find the installation package 14 can be installed, there is no mandatory requirement.
Wechat itself can run in Apple's ios system, and the latest Apple 12 mobile phone is running the latest version of ios system, so there is no pressure to run wechat.