Moses started to lay out God’s plan for worship in the new land. No longer would people worship wherever and whenever they wanted, but instead, they would need to go to the place of worship chosen by God, a place chosen by god and set aside for that purpose:
Deuteronomy 12:13–14, 17–18 Be careful not to sacrifice your burnt offerings just anywhere you like. You may do so only at the place the Lord will choose within one of your tribal territories. There you must offer your burnt offerings and do everything I command you.
17–18But you may not eat your offerings in your hometown—neither the tithe of your grain and new wine and olive oil, nor the firstborn of your flocks and herds, nor any offering to fulfill a vow, nor your voluntary offerings, nor your sacred offerings. You must eat these in the presence of the Lord your God at the place he will choose.
But they could slaughter animals and eat the meat anywhere if it wasn’t part of the worship:
Deuteronomy 12:15,20 But you may butcher your animals and eat their meat in any town whenever you want. … 20 “When the Lord your God expands your territory as he has promised, and you have the urge to eat meat, you may freely eat meat whenever you want.
The point here was that the Israelites were not to copy the people they were displacing: they were to destroy any trace of the old Gods and associated religious practices, and they certainly weren’t to ask about how these other gods should be worshipped or even think about worshipping on the ‘high places’. Instead, the way to worship the one true God was clearly prescribed, and the general eating of meat was well separated from the religious act of sacrificing animals and feasting.