When the Kelvin crashed into the Narada, there was most likely a lot of debris spread into space from the crippled ship. With the loss of a Federation starship, it can be assumed that more would be sent to investigate. When the ships finally got there, the Narada had already made sufficient repairs and left, however, also abandoning the wrecked Kelvin's debris and the debris of its own. In addition to being a 24th century starship (albeit a rather shoddy one), it was enhanced with Borg technology, which contains nanites that could possibly contain information from databanks of the 24th century. Gathering this information, whether in bits and pieces or all together, the Federation was successfully able to upgrade its fleet with advanced technology, which may have had an impact on the aesthe