Hi charliezhufeng,
This version is an important version. It is compatible with version 4.7. Currently there is no any effect if you don’t update to latest version but on late php7 their you might get some deprecated notice on your dashboard. If you have not customized the code then nothing will be lost. So if you have customized the code then its always recommended you to create a child theme and customize the code rather than customizing in parent theme.
Thank you
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