Not really, because I believe it would mess up old saves and I have some going back to when I started playing TS4. Especially regarding the strays, I think it is great they are not in every world. If I feel like it, I can play without seeing a pet all day in game. That does not work for any other life form in TS4. Also, pets really feel most appropriate in Brindelton Bay and in Selvadorada. Actually they feel particularly appropriate in Selvadorada, as a lot of people are used to seeing stray pets on their vacations IRL because they vacation in places that have pretty mild temperatures year-round.
I am all for swimmable oceans in game (rivers and lakes not so much) but I have my doubts whether this could be implemented at all in the old worlds.
I suppose I would feel differently if the changes only affected new saves, in that case the pros could outweigh the cons.