▲这个说法没有错，except that 引导从句时确实可以省略 that，但主要见于口语或非正式文体中。

▲下面的内容摘自朗文词典的 except 词条：

Except is not used to introduce another clause. Use unless or except if, except when, except while, except that. （except 不用于引导另一个从句。可以用 unless，except if，except when，except while 或 except that）:

We won’t go unless you really want to (NOT except you really want to). 我们不打算去了，除非你真的想去。

I cycle to work, except when it rains (NOT except it rains). 除了下雨天之外，我都是骑车去上班的。

In spoken English, people sometimes leave out “that’（在英语口语中，人们有时省略 that）：

The play went well, except (that) a few people forgot their lines. 演出很顺利，只是有几个人忘了台词。