Schubert's Octet in F major, D. 803

I listened to a fair amount of Schubert to-day.  First was an album of some excerpts of symphonies and such, and then (after an album of some Schumann piano pieces) an album of two octets (D. 803 and D. 72, both in F major).  This is only the second time I've listened to both octets in their entirety, although I'm rather familiar with the fifth movement of D. 803 because it also appears on that album of excerpts, which I've had for about a decade.

In any case, while listening to the fourth movement of D. 803, I thought the clarinet part sounded familiar.  At first I thought it was a re-working a phrase that appears elsewhere in the piece, but I later expanded my search, and I found that a very similar phrase starts off the fourth movement of his symphony no. 5.

(notation found here and here)

According to the sources for the notation, Symphony No. 5 was written in 1816, and the octet in 1824.  So, if this is Schubert's reusing past material, he's taking the phrase from his symphony for his octet.

The phrases are pretty simple though, just a rising and then falling diatonic phrase with a steady rhythm, so I'm not sure if this really is an instance of Schubert's reusing material; it might just be a coincidence.  If the phrase were more complex, I'd be more confident in saying that he is borrowing from himself.  Still, it's a similarity I felt worth noting.