I certainly cannot bring to mind any other example of Sibelius seeming to quote another Composer in this way. It may just be a coincidence but even such an authority as Andrew B, says that we cannot be sure.
I can think of examples were Sibelius comes close to the work of others. I am not a practising musician so I hope you will bear with me! Take the Coda from the opening movement of Sibs Third, in which we have Pizzicato strings which move up to a new hymn like figure--now listen to the opening of the finale of Brahms 1st Symphony. Again plucked strings leading to an almost identical chord on woodwind, coincidence or planned.
Even in Sibelius's great Cantata 'Jordens Sang' [Song Of The Earth] opus 93 and, as with the final version of the Fifth dating from 1919, we hear in the third section 'The Fighters' a dynamic figure on the brass that is powerfully Beethovian. It reveals afinities with the opening of The Fidelio Overture.
If nothing else, it bears out what Sibelius had written around this time 'Dont forget your great love of Beethoven. You can worship worse Gods'.--kullervopete.