Whilst die-hard fans and consumers in general have power, for OEM phones there likely needs to be the right desire/fit to strategy from Microsoft, thus enabling their commercial relationships to be initiated and developed. We know Microsoft's publicly available strategy but less about how they'll resource it and enable a seismic shift within markets, especially those outside of their chosen favoured ones.
Their mobile track record hasn't been too strong imo and my sense is that their current strategy will potentially discourage greater volumes of app development that is needed to prevent widespread criticism from outside of the fan base. I may be wrong but I sense that their current target market segments will be discouraged due to their users demand for apps that they'd use for their personal lives, so that handsets would become the 24/7 device, rather than one that would largely have relevance for work related activity. The concept of people needing to transport less devices around is great, which continuum helps to satisfy. If people still resort to having a mobile on another platform, so that they have access to service needs addressed via non-Window's apps, then it undermines that strategy, creating ill-feeling amongst end users; that will feed up to buyers within such organisations and would deter them against future implementation and purchases.
Sure, a loyal fan base has influence but Microsoft, even if targeting a niche segment in the market, isn't operating in isolation from a wider market that has dominant players addressing personal and business needs. In the end people aren't, for example, built to only have business or personal needs, we have both - and our needs run all through the day.