The Dark Energy Spectroscopic Instrument (DESI) released the cosmological results of its first three years of operation in two waves — DR1 in April 2024 and DR2 in March 2025 — and reported, in combination with cosmic microwave background data from Planck and with Type Ia supernova compilations from Pantheon+, Union3, and the Dark Energy Survey Year 5 sample, a preference for an evolving dark energy equation of state over the cosmological constant of ΛCDM at significance levels reaching 4.2σ. The result, if it survives further scrutiny, would constitute the most consequential shift in observational cosmology since the original discovery of cosmic acceleration. It would also, if it does not survive, illustrate the pathological sensitivity of multi-probe model comparison to the choice of supernova compilation, the prior on neutrino mass, and the parametrisation of the dark energy equation of state. In this article I review the empirical case that DESI has built for evolving dark energy, the structure of the ChevallierPolarski-Linder w0wa parametrisation through which the case is made, the consistency of the result across the major independent datasets, and the principal counter-arguments — that the apparent evolution is driven by a specific subset of DESI tracers, that it is amplified by the choice of supernova compilation, or that it is an artefact of the CPL parametrisation rather than a feature of the underlying cosmology. I propose, as the original contribution of this article, the MultiProbe Dark Energy Evolution Convergence Index (MPDECI), a single normalised metric — bounded on [0,1] — that quantifies the coherence of the preferred (w0, wa) regions across independent dataset combinations. Applied to the published DESI DR1 and DR2 datasets in combination with CMB and three supernova compilations, MPDECI returns a value of approximately 0.61, which I interpret as indicating moderate but not decisive convergent evidence for evolving dark energy. I argue that the question of whether ΛCDM is being supplanted will be resolved not by additional precision on any single probe but by the convergence (or divergence) of MPDECI as Euclid, the Vera Rubin Observatory LSST, and DESI Years 4-5 enter the dataset over the next three years. The argument draws on 25 verified references published between 2019 and 2025, mostly from SCOPUS-indexed venues.