No, as the article pointed out, Black Lightning production is in Atlanta, all the other shows are in Vancouver. It was pitched to several networks, Fox committed to a pilot. So from the very earliest stages, everything about production precluded the idea of it sharing the “Arrowverse”. Fox eventually backed down, it was shopped around again, CW bit and they reshot the pilot anyway, but there’s enough in motion at that point that it makes sense it’s still not planned to crossover.
Of course now that it’s at the CW, there’s a better chance that it could someday crossover than if it actually ended up on Fox, but the reasons it’s not going to start out that way seem pretty straightforward. The idea that they’d wait and see if it was successful before crossing over doesn’t really mesh with the realities of production.