But that makes absolutely no sense. There's zero reason to put something like that in when it's frankly, irrelevant.
It is very relevant, it just does not refer to the action IMO.
You can't for example ready Command to trigger when the enemy runs around the corner. The reason is the "normal" way you cast that spell requires you to see the target and you can't see it before the enemy runs around the corner.
You can't say when the Orc gets within 30 feet of me I cast Tasha's Hiedous Laughter because THL requires the target to be within 30 feet of you when you cast it.
Then you have all the mechanics associated with spell components.
That is the kind of thing I think they mean by normal. I don't think they mean the action they are using and I don't think this for multiple reasons:
1. I believe if they wanted you to use a Magic action (in addition to a Ready action) they would have stated this explicitly as they do elsewhere when a Magic action is specifically required for things. They would not have assumed people would come to that conclusion from the use of the word "normal"
2. In 2024 using 2 actions on a single turn is very abnormal and using two actions at the same time is flat prohibited and nothing in the verbiage suggests this restriction is waived. In this respect it is far more abnormal to use two actions on your turn then it is to cast a spell with a casting time of 1 action without using the Magic action.
3. The verbiage "ready a spell" makes it clear they want different mechanics for using the ready action with a spell than with the Magic action generally.
You only put the "normal" phrasing into the Ready Action if it's being cast as normal for the Magic Action that you have chosen when you picked Ready Action.
Nothing in the verbiage indicates to me that this is why they put the word "normal" in there and this intepretation is inconsistent with the rest of the PHB and DMG where they repeatedly and often in a redundant fashion state that a Magic action must be used to do a certain thing.
Given the wording throughout the rest of the PHB and DMG, if the intent was for "ready a spell" to use the Magic action they would have said this explicitly and not relied on an implicit meaning interpreted from the word "normal".