Can a Beastblade Magus take Extra Arcana at 3rd?

[Markov Spiked Chain]

This seems like a grey area in the archetype rules, or maybe just the wording for Beastblade.

Quote:

Familiar (Ex)

At 3rd level, the beastblade gains the familiar magus arcana.

This ability replaces the magus arcana gained at 3rd level.

It seems pretty clear that you still have a/the Magus Arcana feature, and this just restricts your choice at level 3. But the wording is a little funky and I could see someone argue that it's a totally different class feature that just happens to give you an Arcana and doesn't satisfy the pre-req for Extra Arcana.

[kestral287]

You have a Magus Arcana. You're good.

[Helcack]

Yes, as it specifically gives you the arcana so you have the class feature.

[Cyrad]

Yep, you're right. Like the others say, it gives you a magus arcana. If you have a magus arcana, you have the magus arcana class feature.