Help with FOI re exempting Lifetime/Help to Buy ISAs from UC capital limit

On 9 June 2022 PM Boris Johnson announced:

“We’re going to explore discounting Lifetime and Help to Buy ISA savings from Universal Credit eligibility rules. Not letting anyone claim benefits while sitting on vast savings pots that they could be drawing on. That’s not the people we’re targeting here. But making it easier for hard-working people to put away a little each month until they have enough for a deposit on their first home.”

Source: https://www.gov.uk/government/speeches/prime-ministers-housing-speech-9-june-2022

I submitted an FOI request to find out if these plans were still under consideration by the DWP.

Yesterday I received a response:

“We are able to confirm that the information you seek is held by the Department.  However, we are engaging an exemption from disclosure because it relates to the formulation or development of government policy – Section 35(1)(a) of the Freedom of Information Act. This exemption protects the private space within which Ministers and their policy advisers can develop policies without the risk of premature disclosure.”

Source: https://www.whatdotheyknow.com/request/universal_credit_and_lifetime_is#incoming-2429403

I’m not too familiar with FOI requests so looking for guidance on whether this is worth challenging?