No. Vedic Maths teaches different techniques to solve any problem. Once they learn Vedic Maths, students feel more confident in doing Maths they learn in school because they are now equipped with alternative solutions.
Both Abacus and Vedic Maths are totally different. Abacus is a Chinese system of doing calculations using a calculating aid. Vedic Maths is a subject of Indian origin derived from the Vedas.
Abacus has its own usefulness. It can help in doing arithmetic calculations (which was the purpose for its invention). But it has no room for Compound Multiplication, Squaring, Cubing, Algebra, etc. These topics and much more can be learnt using Vedic Maths with ease. Moreover, there are no alternate ways to perform a calculation in Abacus, but in Vedic Maths, there are multiple options to do a single calculation.