The answer is positive and this is not difficult (a normal families argument). The boundary of the Mandelbrot set is the set of $J$-instability. Every point $c_0$ of this set is a limit of $c_n$ such that $z\mapsto z^2+c_n$ has a superattracting cycle. So actually hyperbolic components accumulate to every boundary point of $M$.

(MLC is related to a much harder statement, Fatou conjecture, that interior of $M$ consists of hyperbolic components).

Refs: M. Lyubich, Some typical properties of the dynamics of rational mappings, English transl.: Russian Math surveys, 38, 1983, or

M. Lyubich, The dynamics of rational transforms: the topological picture, Russ. Math. Surv. 41, No. 4, 43-117 (1986);

The answer is positive and this is not difficult (a normal families argument). The boundary of the Mandelbrot set is the set of $J$-instability. Every point $c_0$ of this set is a limit of $c_n$ such that $z\mapsto z^2+c_n$ has a superattracting cycle. So actually hyperbolic components accumulate to every boundary point of $M$.

(MLC is related to a much harder statement, Fatou conjecture, that interior of $M$ consists of only hyperbolic components).

Refs: M. Lyubich, Some typical properties of the dynamics of rational mappings, English transl.: Russian Math surveys, 38, 1983, or

M. Lyubich, The dynamics of rational transforms: the topological picture, Russ. Math. Surv. 41, No. 4, 43-117 (1986);

The answer is positive and this is not difficult. The boundary of the Mandelbrot set is the set of $J$-instability. Every point $c_0$ of this set is a limit of $c_n$ such that $z\mapsto z^2+c_n$ has a superattracting cycle.

Ref. M. Lyubich, Some typical properties of the dynamics of rational mappings, English transl.: Russian Math surveys, 38, 1983.

The answer is positive and this is not difficult (a normal families argument). The boundary of the Mandelbrot set is the set of $J$-instability. Every point $c_0$ of this set is a limit of $c_n$ such that $z\mapsto z^2+c_n$ has a superattracting cycle. So actually hyperbolic components accumulate to every boundary point of $M$.

(MLC is related to a much harder statement, Fatou conjecture, that interior of $M$ consists of hyperbolic components).

Refs: M. Lyubich, Some typical properties of the dynamics of rational mappings, English transl.: Russian Math surveys, 38, 1983, or

M. Lyubich, The dynamics of rational transforms: the topological picture, Russ. Math. Surv. 41, No. 4, 43-117 (1986);