The tipsters didn't say for certain that Spotify would launch this revised free access on the 24th, but the announcement is expected "within a couple weeks" -- it would be odd to unveil a major update like this separately from whatever else appears on the 24th.
The company has lately been willing to limit free users' access to new songs in a bid to both please labels and improve its bottom line, but it still has to cater to them. It's not just because they still outnumber subscribers (Spotify reported 71 million paying users versus 157 million total as of this writing) -- it's that the free tier is often the gateway to becoming a subscriber. The more alluring no-charge access is, the more likely it is that you stick around and consider paying to get unfettered listening. That's crucial when Apple Music is reportedly catching up to Spotify and could have more paying members (Apple's only option after the trial period) as soon as the summer.