  The electroweak (EW) sector of the Minimal Supersymmetric Standard Model
(MSSM) can account for variety of experimental data. The EW particles with
masses of a few hundred GeV evade the LHC searches owing to their small
production cross sections. Such a light EW sector can in particular explain the
reinforced $4.2\,\sigma$ discrepancy between the experimental result for the
anomalous magnetic moment of the muon, \gmin2, and its Standard Model (SM)
prediction. The lightest supersymmetric particle (LSP), assumed to be the
lightest neutralino, $\tilde{\chi}_1^0$, as a Dark Matter (DM) candidate is
furthermore in agreement with the observed limits on the DM content of the
universe. Here the Next-to LSP (NLSP) serves as a coannihilation partner and is
naturally close in mass to the LSP. Such scenarios are also to a large extent
in agreement with negative results from Direct Detection (DD) experiments. The
DM relic density can fully be explained by a nearly pure bino or a mixed
bino/wino LSP. Relatively light wino and higgsino DM, on the other hand,
remains easily below the DM relic density upper bound. Using the improved
limits on $(g-2)_\mu$, we explore the mass ranges of the LSP and the NLSP in
their correlation with the DM relic density for bino, bino/wino, wino and
higgsino DM. In particular analyze the sensitivity of future DM DD experiments
to these DM scenarios. We find that higgsino, wino and one type of bino
scenario can be covered by future DD experiments. Mixed bino/wino and another
type of bino DM can reach DD cross sections below the neutrino floor. In these
cases we analyze the complementarity with the (HL-)LHC and future $e^+e^-$
linear colliders. We find that while the prospects for the HL-LHC are
interesting, but not conclusive, an $e^+e^-$ collider with $\sqrt{s} \le 1$ TeV
can cover effectively all points of the MSSM that may be missed by DD
experiments.
