Honestly, it makes no real difference, because when it reopens we can very easily retag the node, which is still there.

But if that is important to you, here is what I’ll do here: restore it so that it shows again as a restaurant on the map, but setting its opening hours to "off".

Most good apps like OsmAnd correctly manage this.  Some apps ignore them and will show La Grande Terrasse just like any restaurant here and will send people there.