No it is not true, it all comes down to the size of the loans you are pursuing.
Government loans have limits on number of properties and loan size.
There are several lenders who will finance any amount and number of properties.
But lenders will want to see if you are Cash flow positive, by doing rental surveys in the
neighborhood you are buying and what is your cost to Own and Maintain the property.
Prudent to buy several Condos and Town Homes that have been foreclosed in many fine
areas sometimes ranging from $150K to $250K, and renting them out.