I think you are fine. The reactivity would be different depending on your recipe. Is it mayo forward or vinegar forward? Pro-caterers dont seem to hesitate to use foil for nearly everything. I think for overnight or short term storage its fine. If I were saving leftovers I would transfer to glass. I use almost all glass for storage these days. Pyrex with the plastic lids that you can order replacements for.
You can also find some cheap plastic bowls at the, what used to be, dollar stores. That's what I have done for bringing food to a gathering where you just want to walk away. Same thing with utensils. The host can either toss everything in the trash or decide to salvage the plastic-ware.
There are some people who are concerned about foil and health effects, but there are also people who feel the same about plastic. I even ran in to an article where someone was smoking coleslaw in an aluminum pan. Good grief, I got over that "everything must taste like smoke" thing years ago!
This article is adjacent to your question in that it speaks of aluminum containers and coleslaw. Also has a myth-buster or two.