A Nigerian here, actually they reminded people several months ago however the policy to block mobile lines is just a bad idea. First of all, Nigeria is currently ravaged by terrorism which the government has refused to solve (there's a reason for that), the government then came up with a supposedly bright idea to have every Nigerian link their mobile number with their national ID card number for the purpose of combating terrorism.
This prompted people to start complying and it got to a point where the government had a chance to prove that indeed this policy could help tackle terrorism but guess what, they failed woefully.
One particular state in Nigeria known as Zamfara was heavily hit by local terrorists and instead of the government to send in military support to save the people there or atleast track people's phones to locate terrorists, they instead chose to turn off all the mobile networks in Zamfara state. No one could call out as there was no cell service. Despite this, the terrorists continued to operate freely.
This is why the policy to block phone lines in Nigeria makes no sense as the government themselves are the ones responsible for Terrorism in Nigeria. They protect these criminals and in some cases give them amnesty.