That's not the place to stop. Keep reading and according to the story it's clear Peter is not aware of the meaning of the vision. Why is he wondering about it? vrs 17
Again, according to the story, Peter later testifies to the meaning of the vision himself - not to call any man unclean. vrs 28. So unless Peter is going to eat Cornelius or Gentiles in general, then it should be as clear that the vision has nothing to do with a change in the dietary law.
There's certainly some merit to that argument but the fact that unclean animals were shown in the vision does lead me to wonder why the Spirit wouldn't have just provided a vision of unclean people being considered clean, maybe lepers being cleansed or similar.
There are other things that suggest the dietary laws given to the Jews don't apply to the Gentiles:
Gal 2:11-16 NKJV Now when Peter had come to Antioch, I withstood him to his face, because he was to be blamed; (12) for before certain men came from James, he would eat with the Gentiles; but when they came, he withdrew and separated himself, fearing those who were of the circumcision. (13) And the rest of the Jews also played the hypocrite with him, so that even Barnabas was carried away with their hypocrisy. (14) But when I saw that they were not straightforward about the truth of the gospel, I said to Peter before them all, "If you, being a Jew, live in the manner of Gentiles and not as the Jews, why do you compel Gentiles to live as Jews? (15) We who are Jews by nature, and not sinners of the Gentiles, (16) knowing that a man is not justified by the works of the law but by faith in Jesus Christ, even we have believed in Christ Jesus, that we might be justified by faith in Christ and not by the works of the law; for by the works of the law no flesh shall be justified.
Even Jesus said that we aren't made unclean by the things we eat (I think someone already mentioned it further up)
Mat 15:11 NKJV Not what goes into the mouth defiles a man; but what comes out of the mouth, this defiles a man."
Mat 15:17-20 NKJV Do you not yet understand that whatever enters the mouth goes into the stomach and is eliminated? (18) But those things which proceed out of the mouth come from the heart, and they defile a man. (19) For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies. (20) These are the things which defile a man, but to eat with unwashed hands does not defile a man."
If we are going to try and live by the Jewish law we need to live by all of the law. So we'd have to stop trimming the edges of our beards, stop wearing clothing of mixed fibers, regard women as ceremonially unclean during their monthly cycle and so on.
Putting it all together we can see the idea that Jesus told us that things going into our mouths don't make us unclean, Peter is told not to call the things God cleansed unclean, and we aren't Jews anyway (at least I'm not a Jew), so it's hard to put it all together and conclude anything other than I may eat pork if I so choose.
