Nursing to sleep (or sucking to sleep) is how babies are designed to get to sleep. I think the idea that you need to start weaning them off their 'sleep crutches' comes from people trying to offer advice to fix problems that are not rooted in the baby, but rooted in societies unrealistic expectations of babies and toddlers sleep.
Not many people want to hear that it is still perfectly normal for a baby to want to nurse to sleep at 10months, 1 year maybe even 2years, because that means "What I have to be there every night and every nap time for how long?????", so people search for ways to make this not true. However I strongly believe that it depends on the child. Children of a particular temperament may respond to being laid down while drowsy from about 4-5 months thus "proving" that it can be done, and reinforcing the myth that therefore everyone "should" do it. This makes parents of babies who scream hysterically when put down to feel like they are doing something wrong, or they've created a bad sleeper, which is IMO b*llsh*t.
Babies are not fixed beings, they change constantly in response to developmental stages, so it is hard to believe they can fit in to habitual patterns if those patterns don't meet their needs.
Of course you can try to use helpful sleep aids like relaxing sleep environments etc., so that when your child is ready the transition is easier and more familiar but a 2 month old is so young and so reliant on you for everything that stressing about sleep habits will not do anyone any good.