What happened to the spren of 1st and second ideal radiants during the recreance?

[Stormtide_Leviathan]

So, back in the recreance, all the knights radiant broke their oaths, and the spren of those knights became "dead" shardblades that roshar fought over for centuries. But not all radiants have shardblades. From everything we've seen, you have to be at least of the third ideal. So what about all those spren bonded to first and second ideal radiants? They couldn't have gotten off scott-free and survived because then the spren would know more about the recreance and why it happened which, as we saw in ROW, they don't. Did they become deadeyes too, that don't have an associated shardblade? Did they somehow become blades? Did things just work differently back then for some reason and all knights got shardblades?

[Rg2045]

I think the radiants were such a prevalent part of society that people could swear up to the third ideal pretty quickly, something on the coppermind mentions the bondsmiths squires went their whole life’s without bonding a spren but if they did they would have been a 5th ideal radiant. 

[cometaryorbit]

Still there should have been a few 1st or 2nd ideal radiants around and the spren shouldn't have lost so much of the knowledge...

Syl's temporary death in WoR (Kaladin was 2nd Ideal then) probably is what happened, only not reversed later-- the bond broke and the spren died, but no Blade appeared in the Physical Realm.

[Treamayne]

There has been some discussion on this topic in these threads.

But the real answer is simply RAFO. We can theorize, but there isn't yet enough information to know for sure.