Interleaving over OFDM symbols in same transmission
Interleaving data that can be contained in one OFDM symbol between $n$ OFDM symbols will significantly reduce your bitrate and spectral efficiency by a factor of $\frac{1}{n}$. The advantage of doing this would be to increase your resilience to short bursts of noise, but only over $n$ symbols, at the cost of reducing your bitrate by $\frac{1}{n}$. I don't think many applications (if any) would benefit from this.

Edit: I think my initial response wasn't right. Suppose you're interleaving $n=10$ symbols with each other over 10 symbols, and only after you receive the whole block of 10 symbols can you read the code. The amount of information transmitted over the channel over time is the same as when symbols aren't interleaved, there is just some additional latency for the receiver to get the message. As long as your data can wait the extra time, it's worth it for your data to be that much more resilient to noise.