Hmmm! Could guarantee improvements, as depends what the issue is.
Later routers do tend to have more range and better correction.
My 'trick' helps by making a short term disconnection less noticeable, because the DHCP server is not looking up and allocating a free address to the iPad every time it reconnects.
If you have a lot of local WiFi activity, your old router may be getting swamped, if you do change, don't buy the cheapest.