This filter on to put $args passed into comment_form() in comments.php of the theme to match what was set prior to framework 2.5. This will make updating older themes easier, so we don't have to update their comment form styling.

comments-legacy.php

<?php
/**
 * Put comment args back the way they were prior to framework 2.5
 */
function theme_comment_form_args( $args, $commenter, $req, $aria_req ) {
	$commenter = wp_get_current_commenter();
	$req = get_option( 'require_name_email' );
	$aria_req = ( $req ? " aria-required='true'" : '' );
	$args = array(
		'fields' => array(
			'author' => '<p class="comment-form-author"><input id="author" class="form-control" name="author" type="text" value="' . esc_attr( $commenter['comment_author'] ) . '" size="30"' . $aria_req . ' />' .
						'<label for="author">' . themeblvd_get_local( 'name' ) . ( $req ? '<span class="required">*</span>' : '' ) . '</label></p>',
			'email'  => '<p class="comment-form-email"><input id="email" class="form-control" name="email" type="text" value="' . esc_attr(  $commenter['comment_author_email'] ) . '" size="30"' . $aria_req . ' />' .
						'<label for="email">' . themeblvd_get_local( 'email' ) . ( $req ? '<span class="required">*</span>' : '' ) . '</label></p>',
			'url'    => '<p class="comment-form-url"><input id="url" class="form-control" name="url" type="text" value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30" />' .
						'<label for="url">' .themeblvd_get_local( 'website' ) . '</label></p>'
		),
		'comment_field'			=> '<p class="comment-form-comment"><textarea id="comment" class="form-control" name="comment" cols="45" rows="10" aria-required="true"></textarea></p>',
		'title_reply'			=> themeblvd_get_local( 'title_reply' ),
		'title_reply_to'		=> themeblvd_get_local( 'title_reply_to' ),
		'cancel_reply_link'		=> themeblvd_get_local( 'cancel_reply_link' ),
		'label_submit'			=> themeblvd_get_local( 'label_submit' )
	);
	return $args;
}
add_filter( 'themeblvd_comment_form', 'theme_comment_form_args', 10, 4 );