My understanding was the bridge south of Wayatinah has been closed since 2016 and had been dismantled but a quick Google revealed it was actually fixed about a year ago - wonders will never cease

That said, the 'best' vehicular access should still be able to get to Wylds Craig trailhead via Tiger Road (25km in from Maydena/Gordon River Road end) without issue. The affected area is well north of the turnoff, and a few km further north of the old, long-closed bridge just off Florentine Road to Tiger Road, which isn't vehicle passable unless the river level is super low and you're able to ford the river in a suitable 4WD. You can walk the bridge and the remaining road up to the trailhead, of course, but it adds 4km/1hr walking each way and isn't necessary unless Tiger Road is a mess of fallen trees. Best to take some kind of saw when driving in that area, as blown down trees are, ahem, extremely common.