Suppose that $A, B \subset B(\mathcal{H})$ are $C^*$-algebras.
Assume that $\{p_n\} \subset B(\mathcal{H})$ is a monotone sequence of projections such that:
- $p_n \rightarrow 1$ in strong operator topology
- $\forall n$ $p_n A p_n \simeq p_n B p_n$
- Each $p_n A p_n$ is finite dimensional
Is it true that $A \simeq B$ ?
No.
For any such sequence $\{p_n\}$ with each $p_n$ of finite rank, take $A=B(\mathcal H)$ and $$ B=\overline{ \{b\in B(\mathcal H):\ \exists n,\ b=p_nbp_n\}}.$$
Then $p_nAp_n=p_nBp_n$ for all $n$, but $B$ is separable while $A$ is non-separable.