I did it myself in the first days that the sequence was available and came to the same conclusion that this is almost certainly natural in origin and it helps to point out that bats are the most genetically diverse among mammals representing around 1 in 5 mammal species. There aren't that many bat genome sequences that have been performed and so it isn't completely unexpected to find that the spike protein has recombined with a sequence that isn't known. You can however do the translation to amino acid sequence and then search just that spike sequence against known proteins in NCBI and find that it is quite close on the protein level to other known bat proteins, at least in part.

I don't think it is engineered, however it still could be a strain that was collected and analyzed at the Wuhan lab. I don't know if we will ever have the full story on that possibility.